item -- MessageRoleBinding instance.

def IsLiteral(item):
    """item -- MessageRoleBinding instance.
    """
    if not isinstance(item, WSDLTools.MessageRoleBinding):
        raise TypeError, 'IsLiteral takes 1 argument of type WSDLTools.MessageRoleBinding'
    sbb = None
    if item.type == 'input' or item.type == 'output':
        sbb = item.findBinding(WSDLTools.SoapBodyBinding)
    if sbb is None:
        raise ValueError, 'Missing soap:body binding.'
    return sbb.use == 'literal'