Python doctest file to test generation of a WPS request from input arguments.
The specific request involves a "bbox" process submitted to the Emu WPS service
(https://github.com/bird-house/emu).

Imports

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

Process input/output arguments

    >>> processid = "bbox"
    >>> bbox = BoundingBoxDataInput([51.9, 7.0, 53.0, 8.0])
    >>> inputs = [ ("bbox", bbox)]

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_EmuExecuteRequest11.xml'), 'rb').read()
    >>> compare_xml(request, _request)
    True
