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

 """Close file from its name"""

        filename = osp.abspath(to_text_string(filename))
        index = self.editorstacks[0].has_filename(filename)
        if index is not None:
            self.editorstacks[0].close_file(index)