code: public FormattedStringBuilder fillOrCutBuffer(int newLength, char c) {
          if (newLength < _delegate.length()) {
              _delegate = new StringBuilder(_delegate.substring(0, newLength));
              return this;
          }
          for (int i = _delegate.length(); i < newLength; i++ ) {
              _delegate.append(c);
          }
          return this;
      }
docs: Attempts to append <tt>c</tt> until the buffer gets the length <tt>
  newLength</tt>. If the buffer is already longer than <tt>newLength</tt>,
  then the internal strings is cut to <tt>newLength</tt>.
  @param newLength New length of the returned buffer.
  @param c Character to append.
  @return The updated instance of FormattedStringBuilder.