@Override
  public String toString() {
    ExecutableElement executable = executableElement;
    Element nameSource =
        executable.getKind() == ElementKind.CONSTRUCTOR
            ? executable.getEnclosingElement()
            : executable;
    return nameSource.getSimpleName()
        + executable.getParameters().stream()
            .map(v -> v.asType() + " " + v.getSimpleName())
            .collect(joining(", ", "(", ")"));
  }
The Java code to invoke this constructor or method, up to just before the opening {@code (}.
value/src/main/java/com/google/auto/value/processor/Executable.java