code: public static String extractMavenPropertyName(String propName) {
          Matcher matcher = Pattern.compile(MAVEN_PROPERTY_REGEXP).matcher(propName);
          if (matcher.matches()) {
              return matcher.group(1);
          } else {
              return null;
          }
      }
docs: Extract from a Maven property which is in the form ${name} the name.
  
  @param propName property name to extrat
  @return the pure name or null if this is not a property name