RaCoCo result: Red::AST::Union

# Red::AST::Union 53.3%

    use Red::AST;
    use Red::AST::MultiSelect;
    unit class Red::AST::Union does Red::AST::MultiSelect;

    has Red::AST @.selects;

    method new(*@selects) {
        nextwith :selects(Array[Red::AST].new: |@selects)
    }

    method returns { Red::Model }

    method args { flat @!selects>>.args }

    method tables(::?CLASS:D:) {
        (flat @!selects».?tables).grep(-> \v { v !=:= Nil }).unique
    }
    method find-column-name {}

    method union($sel) {
        if $sel ~~ ::?CLASS {
            self.union: $_ for $sel.selects
        } else {
            self.selects.push: $sel
        }
        self
    }