code: public static String removeStart(String str, String remove) {
          if (isNullOrEmpty(str) || isNullOrEmpty(remove)) {
              return str;
          }
  
          if (str.startsWith(remove)) {
              return str.substring(remove.length());
          }
  
          return str;
      }
docs: <p>Removes a substring only if it is at the start of a source string,
  otherwise returns the source string.</p>
  <p/>
  <p>A {@code null} source string will return {@code null}.
  An empty ("") source string will return the empty string.
  A {@code null} search string will return the source string.</p>
  <p/>
  <pre>
  StringUtils.removeStart(null, *)      = null
  StringUtils.removeStart("", *)        = ""
  StringUtils.removeStart(*, null)      = *
  StringUtils.removeStart("www.domain.com", "www.")  = "domain.com"
  StringUtils.removeStart("abc", "")    = "abc"
  </pre>
  
  @param str    the source String to search, may be null
  @param remove the String to search for and remove, may be null
  @return the substring with the string removed if found,
  {@code null} if null String input