Python doctest file to test generation of a WPS request from input arguments.
The specific request involves a "v.net.path" process submitted to the PML WPS service.

Imports

    >>> from __future__ import (absolute_import, division, print_function)
    >>> from tests.utils import resource_file, compare_xml
    >>> from owslib.wps import WebProcessingService, WPSExecution
    >>> from owslib.etree import etree

Process input/ouutput arguments

    >>> processid = "v.net.path"
    >>> inputs = [ ("input","http://rsg.pml.ac.uk/wps/example/graph.gml"),
    ...            ("file","1 -960123.1421801624 4665723.56559387 -101288.65106088226 5108200.011823481")]

Build XML request for WPS process execution

    >>> execution = WPSExecution()
    >>> requestElement = execution.buildRequest(processid, inputs)
    >>> request = etree.tostring( requestElement )

Compare to cached XML request

    >>> _request = open(resource_file('wps_PMLExecuteRequest6.xml'), 'rb').read()
    >>> compare_xml(request, _request)
    True
