code: static boolean prohibited(final int codepoint) {
          return nonAsciiSpace((char) codepoint)
                  || asciiControl((char) codepoint)
                  || nonAsciiControl(codepoint)
                  || privateUse(codepoint)
                  || nonCharacterCodePoint(codepoint)
                  || surrogateCodePoint(codepoint)
                  || inappropriateForPlainText(codepoint)
                  || inappropriateForCanonical(codepoint)
                  || changeDisplayProperties(codepoint)
                  || tagging(codepoint);
      }
docs: Return true if the given {@code codepoint} is a prohibited character as defined by
  <a href="https://tools.ietf.org/html/rfc4013#section-2.3">RFC 4013, Section 2.3</a>.