code: @Override
      public GetCertificateResult getCertificate(GetCertificateRequest request) {
          request = beforeClientExecution(request);
          return executeGetCertificate(request);
      }
docs: <p>
  Retrieves a certificate from your private CA. The ARN of the certificate is returned when you call the
  <a>IssueCertificate</a> operation. You must specify both the ARN of your private CA and the ARN of the issued
  certificate when calling the <b>GetCertificate</b> operation. You can retrieve the certificate if it is in the
  <b>ISSUED</b> state. You can call the <a>CreateCertificateAuthorityAuditReport</a> operation to create a report
  that contains information about all of the certificates issued and revoked by your private CA.
  </p>
  
  @param getCertificateRequest
  @return Result of the GetCertificate operation returned by the service.
  @throws RequestInProgressException
  Your request is already in progress.
  @throws RequestFailedException
  The request has failed for an unspecified reason.
  @throws ResourceNotFoundException
  A resource such as a private CA, S3 bucket, certificate, or audit report cannot be found.
  @throws InvalidArnException
  The requested Amazon Resource Name (ARN) does not refer to an existing resource.
  @throws InvalidStateException
  The private CA is in a state during which a report or certificate cannot be generated.
  @sample AWSACMPCA.GetCertificate
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/acm-pca-2017-08-22/GetCertificate" target="_top">AWS API
  Documentation</a>