code: public void setRtfDocument(RtfDocument doc) {
          this.document = doc;
          if(document != null) {
              this.fontNumber = document.getDocumentHeader().getFontNumber(this);
          }
          if(this.color != null) {
              this.color.setRtfDocument(this.document);
          }
      }
docs: Sets the RtfDocument this RtfFont belongs to
  
  @param doc The RtfDocument to use