babel-preset-env: `DEBUG` option

Using targets:
{
  "chrome": "54",
  "edge": "13",
  "firefox": "49",
  "ie": "10",
  "ios": "9",
  "safari": "7"
}

Modules transform: commonjs

Using plugins:
  check-es2015-constants {"edge":"13","firefox":"49","ie":"10","ios":"9","safari":"7"}
  transform-es2015-arrow-functions {"ie":"10","ios":"9","safari":"7"}
  transform-es2015-block-scoped-functions {"ie":"10","ios":"9","safari":"7"}
  transform-es2015-block-scoping {"edge":"13","firefox":"49","ie":"10","ios":"9","safari":"7"}
  transform-es2015-classes {"ie":"10","ios":"9","safari":"7"}
  transform-es2015-computed-properties {"ie":"10","safari":"7"}
  transform-es2015-destructuring {"edge":"13","firefox":"49","ie":"10","ios":"9","safari":"7"}
  transform-es2015-duplicate-keys {"ie":"10","safari":"7"}
  transform-es2015-for-of {"edge":"13","firefox":"49","ie":"10","ios":"9","safari":"7"}
  transform-es2015-function-name {"edge":"13","firefox":"49","ie":"10","ios":"9","safari":"7"}
  transform-es2015-literals {"firefox":"49","ie":"10","safari":"7"}
  transform-es2015-object-super {"ie":"10","ios":"9","safari":"7"}
  transform-es2015-parameters {"edge":"13","firefox":"49","ie":"10","ios":"9","safari":"7"}
  transform-es2015-shorthand-properties {"ie":"10","safari":"7"}
  transform-es2015-spread {"ie":"10","ios":"9","safari":"7"}
  transform-es2015-sticky-regex {"ie":"10","ios":"9","safari":"7"}
  transform-es2015-template-literals {"ie":"10","safari":"7"}
  transform-es2015-typeof-symbol {"ie":"10","safari":"7"}
  transform-es2015-unicode-regex {"ie":"10","ios":"9","safari":"7"}
  transform-regenerator {"firefox":"49","ie":"10","ios":"9","safari":"7"}
  transform-exponentiation-operator {"edge":"13","firefox":"49","ie":"10","ios":"9","safari":"7"}
  transform-async-to-generator {"chrome":"54","edge":"13","firefox":"49","ie":"10","ios":"9","safari":"7"}
  syntax-trailing-function-commas {"chrome":"54","edge":"13","firefox":"49","ie":"10","ios":"9","safari":"7"}

Using polyfills:
  es6.typed.array-buffer {"ie":"10","ios":"9","safari":"7"}
  es6.typed.int8-array {"ie":"10","ios":"9","safari":"7"}
  es6.typed.uint8-array {"ie":"10","ios":"9","safari":"7"}
  es6.typed.uint8-clamped-array {"ie":"10","ios":"9","safari":"7"}
  es6.typed.int16-array {"ie":"10","ios":"9","safari":"7"}
  es6.typed.uint16-array {"ie":"10","ios":"9","safari":"7"}
  es6.typed.int32-array {"ie":"10","ios":"9","safari":"7"}
  es6.typed.uint32-array {"ie":"10","ios":"9","safari":"7"}
  es6.typed.float32-array {"ie":"10","ios":"9","safari":"7"}
  es6.typed.float64-array {"ie":"10","ios":"9","safari":"7"}
  es6.map {"edge":"13","firefox":"49","ie":"10","ios":"9","safari":"7"}
  es6.set {"edge":"13","firefox":"49","ie":"10","ios":"9","safari":"7"}
  es6.weak-map {"edge":"13","firefox":"49","ie":"10","safari":"7"}
  es6.weak-set {"edge":"13","firefox":"49","ie":"10","safari":"7"}
  es6.reflect.apply {"ie":"10","ios":"9","safari":"7"}
  es6.reflect.construct {"ie":"10","ios":"9","safari":"7"}
  es6.reflect.define-property {"ie":"10","ios":"9","safari":"7"}
  es6.reflect.delete-property {"ie":"10","ios":"9","safari":"7"}
  es6.reflect.get {"ie":"10","ios":"9","safari":"7"}
  es6.reflect.get-own-property-descriptor {"ie":"10","ios":"9","safari":"7"}
  es6.reflect.get-prototype-of {"ie":"10","ios":"9","safari":"7"}
  es6.reflect.has {"ie":"10","ios":"9","safari":"7"}
  es6.reflect.is-extensible {"ie":"10","ios":"9","safari":"7"}
  es6.reflect.own-keys {"ie":"10","ios":"9","safari":"7"}
  es6.reflect.prevent-extensions {"ie":"10","ios":"9","safari":"7"}
  es6.reflect.set {"ie":"10","ios":"9","safari":"7"}
  es6.reflect.set-prototype-of {"ie":"10","ios":"9","safari":"7"}
  es6.promise {"ie":"10","ios":"9","safari":"7"}
  es6.symbol {"edge":"13","firefox":"49","ie":"10","ios":"9","safari":"7"}
  es6.object.assign {"ie":"10","safari":"7"}
  es6.object.is {"ie":"10","safari":"7"}
  es6.object.set-prototype-of {"ie":"10","safari":"7"}
  es6.function.name {"edge":"13","firefox":"49","ie":"10","ios":"9","safari":"7"}
  es6.string.raw {"ie":"10","safari":"7"}
  es6.string.from-code-point {"ie":"10","safari":"7"}
  es6.string.code-point-at {"ie":"10","safari":"7"}
  es6.string.repeat {"ie":"10","safari":"7"}
  es6.string.starts-with {"ie":"10","safari":"7"}
  es6.string.ends-with {"ie":"10","safari":"7"}
  es6.string.includes {"ie":"10","safari":"7"}
  es6.regexp.flags {"edge":"13","ie":"10","safari":"7"}
  es6.regexp.match {"edge":"13","ie":"10","ios":"9","safari":"7"}
  es6.regexp.replace {"edge":"13","ie":"10","ios":"9","safari":"7"}
  es6.regexp.split {"edge":"13","ie":"10","ios":"9","safari":"7"}
  es6.regexp.search {"edge":"13","ie":"10","ios":"9","safari":"7"}
  es6.array.from {"edge":"13","ie":"10","ios":"9","safari":"7"}
  es6.array.of {"ie":"10","safari":"7"}
  es6.array.copy-within {"ie":"10","safari":"7"}
  es6.array.find {"ie":"10","safari":"7"}
  es6.array.find-index {"ie":"10","safari":"7"}
  es6.array.fill {"ie":"10","safari":"7"}
  es6.array.iterator {"ie":"10","safari":"7"}
  es6.number.is-finite {"ie":"10","safari":"7"}
  es6.number.is-integer {"ie":"10","safari":"7"}
  es6.number.is-safe-integer {"ie":"10","safari":"7"}
  es6.number.is-nan {"ie":"10","safari":"7"}
  es6.number.epsilon {"ie":"10","safari":"7"}
  es6.number.min-safe-integer {"ie":"10","safari":"7"}
  es6.number.max-safe-integer {"ie":"10","safari":"7"}
  es6.math.acosh {"ie":"10","safari":"7"}
  es6.math.asinh {"ie":"10","safari":"7"}
  es6.math.atanh {"ie":"10","safari":"7"}
  es6.math.cbrt {"ie":"10","safari":"7"}
  es6.math.clz32 {"ie":"10","safari":"7"}
  es6.math.cosh {"ie":"10","safari":"7"}
  es6.math.expm1 {"ie":"10","safari":"7"}
  es6.math.fround {"ie":"10","safari":"7"}
  es6.math.hypot {"ie":"10","safari":"7"}
  es6.math.imul {"ie":"10"}
  es6.math.log1p {"ie":"10","safari":"7"}
  es6.math.log10 {"ie":"10","safari":"7"}
  es6.math.log2 {"ie":"10","safari":"7"}
  es6.math.sign {"ie":"10","safari":"7"}
  es6.math.sinh {"ie":"10","safari":"7"}
  es6.math.tanh {"ie":"10","safari":"7"}
  es6.math.trunc {"ie":"10","safari":"7"}
  es7.array.includes {"edge":"13","ie":"10","ios":"9","safari":"7"}
  es7.object.values {"edge":"13","ie":"10","ios":"9","safari":"7"}
  es7.object.entries {"edge":"13","ie":"10","ios":"9","safari":"7"}
  es7.object.get-own-property-descriptors {"edge":"13","firefox":"49","ie":"10","ios":"9","safari":"7"}
  es7.string.pad-start {"chrome":"54","edge":"13","ie":"10","ios":"9","safari":"7"}
  es7.string.pad-end {"chrome":"54","edge":"13","ie":"10","ios":"9","safari":"7"}
  web.timers {"chrome":"54","edge":"13","firefox":"49","ie":"10","ios":"9","safari":"7"}
  web.immediate {"chrome":"54","edge":"13","firefox":"49","ie":"10","ios":"9","safari":"7"}
  web.dom.iterable {"chrome":"54","edge":"13","firefox":"49","ie":"10","ios":"9","safari":"7"}
src/in.js -> lib/in.js