CredentialsBuilder()
           .fromFile("pdfservices-api-credentials.json")
           .build(),
       executionContext = PDFServicesSdk.ExecutionContext.create(credentials),
       ReplacePages = PDFServicesSdk.ReplacePages,
       replacePagesOperation = ReplacePages.Operation.createNew();

 replacePagesOperation.setBaseInput(PDFServicesSdk.FileRef.createFromLocalFile('~/Documents/replacePagesOperationBaseInput.pdf',
 	ReplacePages.SupportedSourceFormat.pdf));
 replacePagesOperation.addPagesForReplace(