docs: protected String nextOtherNumber( int c ) throws IOException 
      {
          //StringBuilder isb = new StringBuilder();
          isb.clear();
          isb.append((char)c);
          int ch;
          while ( (ch = readNext()) != -1 ) {
              if ( StringUtil.isWhitespace(ch) ) {
                  pushBack(ch);
                  break;
              }
              
              if ( ! StringUtil.isOtherNumber(ch) ) {
                  pushBack(ch);
                  break;
              } 
              
              isb.append((char)ch);
          }
          
          return isb.toString();
      }