code: private static String parseHashName(String param) {
          Matcher matcher = hashPattern.matcher(param);
          String name = null;
          while (matcher.find()){
              name = matcher.group(0);
          }
          return name == null? null : name.substring(1, name.length() - 1);
      }
docs: Parses name from hash syntax.
  
  @param param something like this: <code>person[account]</code>
  @return name of hash key:<code>account</code>