def parametrization_name_func(func_name, kwargs):
    """
    Method name generator for parametrized testcases.

    >>> import collections
    >>> parametrization_name_func('test_method',
                               collections.OrderedDict(('foo', 5), ('bar', 10)))
    'test_method__foo_5__bar_10'

    :param func_name: Name of the parametrization target function.
    :type func_name: ``str``
    :param kwargs: The order of keys will be the same as the order of arguments
                   in the original function.
    :type kwargs: ``collections.OrderedDict``

    :return: New testcase method name.
    :rtype: ``str``
    """
    arg_strings = ["{arg}_{{{arg}}}".format(arg=arg) for arg in kwargs]
    template = "{func_name}__" + "__".join(arg_strings)
    return template.format(func_name=func_name, **kwargs)