code: public static boolean contentEqualsIgnoreCase(CharSequence a, CharSequence b) {
          if (a == null || b == null) {
              return a == b;
          }
  
          if (a.getClass() == AsciiString.class) {
              return ((AsciiString) a).contentEqualsIgnoreCase(b);
          }
          if (b.getClass() == AsciiString.class) {
              return ((AsciiString) b).contentEqualsIgnoreCase(a);
          }
  
          if (a.length() != b.length()) {
              return false;
          }
          for (int i = 0; i < a.length(); ++i) {
              if (!equalsIgnoreCase(a.charAt(i),  b.charAt(i))) {
                  return false;
              }
          }
          return true;
      }
docs: Returns {@code true} if both {@link CharSequence}'s are equals when ignore the case. This only supports 8-bit
  ASCII.