code: static boolean charEqualsIgnoreCase(char c1, char c2) {
          return c1 == c2 ||
                  Character.toUpperCase(c1) == Character.toUpperCase(c2) ||
                  Character.toLowerCase(c1) == Character.toLowerCase(c2);
      }
docs: Compares two characters ignoring case.
  
  @param c1  the first
  @param c2  the second
  @return true if equal