code: public boolean checkStartsWith(String str, String start) {
          return str.regionMatches(!isSensitive, 0, start, 0, start.length());
      }
docs: Checks if one string starts with another using the case-sensitivity rule.
  <p>
  This method mimics {@link String#startsWith(String)} but takes case-sensitivity
  into account.
  
  @param str  the string to check, not null
  @param start  the start to compare against, not null
  @return true if equal using the case rules
  @throws NullPointerException if either string is null