code: @Override
      public String parse(final String threshold, final RangeConfig tc) {
          configure(tc);
          return threshold.substring(1);
      }
docs: Parses the threshold to remove the matched braket.
  
  No checks are performed against the passed in string: the object assumes
  that the string is correct since the {@link #canParse(String)} method
  <b>must</b> be called <b>before</b> this method.
  
  @param threshold
  The threshold to parse
  @param tc
  The threshold config object. This object will be populated
  according to the passed in threshold.
  
  @return the remaining part of the threshold