code: func (v *VerbalExpression) StartOfLine() *VerbalExpression {
  	if !strings.HasPrefix(v.prefixes, "^") {
  		v.prefixes = `^` + v.prefixes
  	}
  	return v
  }
docs: // StartOfLine seeks the begining of a line. As EndOfLine you should use
  // SearchOneLine(true) to test multiple lines