docs: public static String substring(final String pSource, final String pBeginBoundaryString, final String pEndBoundaryString,
                                     final int pOffset) {
          // Check offset
          int offset = (pOffset < 0)
                  ? 0
                  : pOffset;
  
          // Find the start index
          int startIndex = pSource.indexOf(pBeginBoundaryString, offset) + pBeginBoundaryString.length();
  
          if (startIndex < 0) {
              return null;
          }
  
          // Find the end index
          int endIndex = pSource.indexOf(pEndBoundaryString, startIndex);
  
          if (endIndex < 0) {
              return null;
          }
          return pSource.substring(startIndex, endIndex);
      }