Makes this request field into a multipart request field.

        This method overrides "Content-Disposition", "Content-Type" and
        "Content-Location" headers to the request parameter.

        :param content_type:
            The 'Content-Type' of the request body.
        :param content_location:
            The 'Content-Location' of the request body.

def make_multipart(self, content_disposition=None, content_type=None,
                       content_location=None):
        """
        Makes this request field into a multipart request field.

        This method overrides "Content-Disposition", "Content-Type" and
        "Content-Location" headers to the request parameter.

        :param content_type:
            The 'Content-Type' of the request body.
        :param content_location:
            The 'Content-Location' of the request body.

        """
        self.headers['Content-Disposition'] = content_disposition or 'form-data'
        self.headers['Content-Disposition'] += '; '.join([
            '', self._render_parts(
                (('name', self._name), ('filename', self._filename))
            )
        ])
        self.headers['Content-Type'] = content_type
        self.headers['Content-Location'] = content_location