code: public static TagKey create(String name) {
      Utils.checkArgument(isValid(name), "Invalid TagKey name: %s", name);
      return new AutoValue_TagKey(name);
    }
docs: Constructs a {@code TagKey} with the given name.
  
  <p>The name must meet the following requirements:
  
  <ol>
  <li>It cannot be longer than {@link #MAX_LENGTH}.
  <li>It can only contain printable ASCII characters.
  </ol>
  
  @param name the name of the key.
  @return a {@code TagKey} with the given name.
  @throws IllegalArgumentException if the name is not valid.
  @since 0.8