code: public boolean isSkipLine(String line) {
          return skipLinePattern != null && line != null && skipLinePattern.matcher(line).matches();
      }
docs: Tells if the given content line must be skipped according to this header definition. The header is outputted
  after any skipped line if any pattern defined on this point or on the first line if not pattern defined.
  
  @param line The line to test.
  @return true if this line must be skipped or false.