code: def GetWSAActionInput(operation):
      
      attr = operation.input.action
      if attr is not None:
          return attr
      portType = operation.getPortType()
      targetNamespace = portType.getTargetNamespace()
      ptName = portType.name
      msgName = operation.input.name
      if not msgName:
          msgName = operation.name + 'Request'
      if targetNamespace.endswith('/'):
          return '%s%s/%s' %(targetNamespace, ptName, msgName)
      return '%s/%s/%s' %(targetNamespace, ptName, msgName)
docs: Find wsa:Action attribute, and return value or the default.