code: private PHSCoverLetter12Document getPHSCoverLetter() {
  
  		PHSCoverLetter12Document phsCoverLetterDocument = PHSCoverLetter12Document.Factory
  				.newInstance();
  		PHSCoverLetter12 phsCoverLetter = PHSCoverLetter12.Factory
  				.newInstance();
          CoverLetterFile coverLetterFile = CoverLetterFile.Factory.newInstance();
  		phsCoverLetter.setFormVersion(FormVersion.v1_2.getVersion());
  		AttachedFileDataType attachedFileDataType = null;
  		for (NarrativeContract narrative : pdDoc.getDevelopmentProposal()
  				.getNarratives()) {
  			if (narrative.getNarrativeType().getCode() != null
  					&& Integer.parseInt(narrative.getNarrativeType().getCode()) == NARRATIVE_PHS_COVER_LETTER) {
  				attachedFileDataType = getAttachedFileType(narrative);
  				if(attachedFileDataType != null){
  					coverLetterFile.setCoverLetterFilename(attachedFileDataType);
  					break;
  				}
  			}
  		}
          phsCoverLetter.setCoverLetterFile(coverLetterFile);
  		phsCoverLetterDocument.setPHSCoverLetter12(phsCoverLetter);
  		return phsCoverLetterDocument;
  	}
docs: This method is used to get PHSCoverLetter12Document attachment from the
  narrative attachments.
  
  @return phsCoverLetter12Document {@link XmlObject} of type
  PHS398CoverLetterDocument.