'Get a description of the calling prototype for this flow.'

@classmethod
def GetCallingPrototypeAsString(cls):

    output = []
    output.append('flow.GRRFlow.StartFlow(client_id=client_id,    ')
    output.append(('flow_name="%s",    ' % cls.__name__))
    prototypes = []
    if cls.args_type:
        for type_descriptor in cls.args_type.type_infos:
            if (not type_descriptor.hidden):
                prototypes.append(('%s=%s' % (type_descriptor.name, type_descriptor.name)))
    output.append(',    '.join(prototypes))
    output.append(')')
    return ''.join(output)
