'Copies the body, in cases where it might be shared with
another request object and that is not desired.
This copies the body in-place, either into a BytesIO object
or a temporary file.'

def copy_body(self):

    if (not self.is_body_readable):
        self.body = ''
    elif (self.content_length is None):
        self.body = self.body_file_raw.read()
        self._copy_body_tempfile()
    else:
        did_copy = self._copy_body_tempfile()
        if (not did_copy):
            self.body = self.body_file.read(self.content_length)
