<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def container(self, name, length, type, *parameters):
 """Define a container with given length. This is a convenience method creating a `Struct` with `length` containing fields defined in `type`. """

        self.new_struct('Container', name, 'length=%s' % length)
        BuiltIn().run_keyword(type, *parameters)
        self.end_struct()