code: public static String getPropertyForSetter(String setterName) {
          if (setterName == null || setterName.length() == 0) return null;
  
          if (setterName.startsWith("set")) {
              String prop = setterName.substring(3);
              return convertValidPropertyMethodSuffix(prop);
          }
          return null;
      }
docs: Returns a property name equivalent for the given setter name or null if it is not a valid setter. If not null
  or empty the setter name is assumed to be a valid identifier.
  
  @param setterName The setter name, must be null or empty or a valid identifier name
  @return The property name equivalent