code: public static boolean equalsIgnoreCase(final CharSequence left, final int leftOffset, final int leftLength,
                                                final CharSequence right, final int rightOffset, final int rightLength) {
          if (leftLength == rightLength) {
              for (int i = 0; i < rightLength; i++) {
                  if (toLowerCase(left.charAt(i + leftOffset)) != toLowerCase(right.charAt(i + rightOffset))) {
                      return false;
                  }
              }
              return true;
          }
          return false;
      }
docs: Returns true if the specified section of the left CharSequence equals, ignoring case, the specified section of
  the right CharSequence.
  
  @param left the left CharSequence
  @param leftOffset start index in the left CharSequence
  @param leftLength length of the section in the left CharSequence
  @param right the right CharSequence to compare a section of
  @param rightOffset start index in the right CharSequence
  @param rightLength length of the section in the right CharSequence
  @return true if equal ignoring case, false otherwise