code: private boolean isWhitespace(char c) {
          if (c > 0x20) {
              return false;
          }
          if ((c == 0x20) || (c == 0x0a) || (c == 0x09) || (c == 0x0d)) {
              return true;
          }
          return false; // illegal ...
      }
docs: Test if a character is whitespace.
  
  <pre>
  [3] S ::= (#x20 | #x9 | #xd | #xa)+
  </pre>
  
  @param c
  The character to test.
  @return true if the character is whitespace.