def _create_credentials_fetcher(self):
        method = self.METHOD

        def fetch_credentials():
            # HTTP headers are case insensitive filter out
            # all duplicate headers and pick one.
            headers = {}
            headers['content-type'] = 'application/x-www-form-urlencoded'
            headers['authorization'] = urllib3.make_headers(

		return input.Clone(output), nil
	}

	for i, expr := range e.selectAST.Expression.Expressions {
		v, err := expr.evalNode(input, e.tableAlias)
		if err != nil {
			return nil, err
		}

		// Pick output column names
		if expr.As != "" {
			output, err = output.Set(expr.As, v)
		} else if comp, ok := getLastKeypathComponent(expr.Expression); ok {
			output, err = output.Set(comp, v)
		} else {

//     createdAfter: "date" # match objects created after "date"
//     createdBefore: "date" # match objects created before "date"
//     tags:
//       - key: "name"
//         value: "pick*" # match objects with tag 'name', with all values starting with 'pick'
//     metadata:
//       - key: "content-type"
//         value: "image/*" # match objects with 'content-type', with all values starting with 'image/'

So, it's really important that you actually read and run the code, and let me know in the comments that you did. 🤓

///

* If the PR can be simplified in a way, you can ask for that, but there's no need to be too picky, there might be a lot of subjective points of view (and I will have my own as well 🙈), so it's better if you can focus on the fundamental things.

### Tests

* Help me check that the PR has **tests**.

        String::class.java == returnType && callArgs.size == 1 && callArgs[0] is List<*>
      ) {
        val peerProtocols = callArgs[0] as List<*>
        // Pick the first known protocol the peer advertises.
        for (i in 0..peerProtocols.size) {
          val protocol = peerProtocols[i] as String
          if (protocol in protocols) {
            selected = protocol

    } else if (exponent > MAX_EXPONENT) {
      return x.signum() * POSITIVE_INFINITY;
    }

    /*
     * We need the top SIGNIFICAND_BITS + 1 bits, including the "implicit" one bit. To make rounding
     * easier, we pick out the top SIGNIFICAND_BITS + 2 bits, so we have one to help us round up or
     * down. twiceSignifFloor will contain the top SIGNIFICAND_BITS + 2 bits, and signifFloor the
     * top SIGNIFICAND_BITS + 1.
     *

@DoNotMock("Use ImmutableRangeMap or TreeRangeMap")
@GwtIncompatible
@ElementTypesAreNonnullByDefault
public interface RangeMap<K extends Comparable, V> {
  /*
   * TODO(cpovirk): These docs sometimes say "map" and sometimes say "range map." Pick one, or at
   * least decide on a policy for when to use which.
   */

  /**
   * Returns the value associated with the specified key, or {@code null} if there is no such value.
   *

 * **Step down considerately**: Members of every project come and go. When somebody leaves or
   disengages from the project, they should make it known and take the proper steps to ensure that
   others can pick up where they left off.

This code is not exhaustive or complete. It serves to distill our common understanding of a
collaborative, shared environment, and goals. We expect it to be followed in spirit as much as in
the letter.

  for (int i = 0; i < num_tasks; i++) {
    int port = tensorflow::testing::PickUnusedPortOrDie();
    job_def->mutable_tasks()->insert(
        {i, tensorflow::strings::StrCat("localhost:", port)});
    LOG(INFO) << "Picked test port: " << port << " for job: " << job_name
              << ", task: " << i;
  }
  return server_def;
}

tensorflow::ServerDef GetServerDef(int num_tasks) {
  return GetServerDef("localhost", num_tasks);

//       createdBefore: "2006-01-02T15:04:05.00Z" # match objects created before "date"
//       tags:
//         - key: name
//           value: pick* # match objects with tag 'name', all values starting with 'pick'
//       metadata:
//         - key: content-type
//           value: image/* # match objects with 'content-type', all values starting with 'image/'
//       size: