<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def get_open_filenames(self):

 """Get the list of open files in the current stack"""

        editorstack = self.editorstacks[0]
        filenames = []
        filenames += [finfo.filename for finfo in editorstack.data]
        return filenames