code: @Nullable
    @CheckReturnValue
    public static String trimStart (@Nullable final String sSrc, @Nullable final String sLead)
    {
      return startsWith (sSrc, sLead) ? sSrc.substring (sLead.length (), sSrc.length ()) : sSrc;
    }
docs: Trim the passed lead from the source value. If the source value does not
  start with the passed lead, nothing happens.
  
  @param sSrc
  The input source string
  @param sLead
  The string to be trimmed of the beginning
  @return The trimmed string, or the original input string, if the lead was not
  found
  @see #trimEnd(String, String)
  @see #trimStartAndEnd(String, String)
  @see #trimStartAndEnd(String, String, String)