<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def make(self, cwl):
 """Instantiate a CWL object from a CWl document."""

        load = load_tool.load_tool(cwl, self.loading_context)
        if isinstance(load, int):
            raise Exception("Error loading tool")
        return Callable(load, self)