Unreachable and weird code

In the following snippet we have

            if parse_headers is False:
                pass
            elif parse_headers is True:
                l = str(l, "utf-8")
                k, v = l.split(":", 1)
                resp_d[k] = v.strip()
            else:
                parse_headers(l, resp_d)

The else part is unreachable and at the same time a call to parse_headers is used.
parse_headers is not a function.

Start by locating the Python file containing the reported snippet and read the surrounding response-header parsing flow. Determine the intended handling of parse_headers when it is False, True, or another value, then verify that the unreachable branch and non-callable reference are resolved without changing valid header parsing behavior.