code: public static PdfFileSpecification fileEmbedded(PdfWriter writer, String filePath, String fileDisplay, byte fileStore[], int compressionLevel) throws IOException {
          return fileEmbedded(writer, filePath, fileDisplay, fileStore, null, null, compressionLevel);
      }
docs: Creates a file specification with the file embedded. The file may
  come from the file system or from a byte array. The data is flate compressed.
  @param writer the <CODE>PdfWriter</CODE>
  @param filePath the file path
  @param fileDisplay the file information that is presented to the user
  @param fileStore the byte array with the file. If it is not <CODE>null</CODE>
  it takes precedence over <CODE>filePath</CODE>
  @param compressionLevel	the compression level to be used for compressing the file
  it takes precedence over <CODE>filePath</CODE>
  @throws IOException on error
  @return the file specification
  @since	2.1.3