<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def visit_FunctionDef(self, node):
 """ Determine this function definition can be inlined. """

        if (len(node.body) == 1 and
                isinstance(node.body[0], (ast.Call, ast.Return))):
            ids = self.gather(Identifiers, node.body[0])
            # FIXME : It mark "not inlinable" def foo(foo): return foo
            if node.name not in ids:
                self.result[node.name] = copy.deepcopy(node)