code: public function replaceString($search, $replace)
      {
          $this->text = str_replace($search, $replace, $this->text);
  
          return $this;
      }
docs: Replace all occurrences of the search string with the replacement string
  
  @param string|array $search  The value being searched for, otherwise known as the needle. An array may be used to designate multiple needles.
  @param string|array $replace The replacement value that replaces found search values. An array may be used to designate multiple replacements.
  
  @return Text