code: @Override
      protected void initializeImpl()
      {
          //get values
          this.submitCommand=this.getConfigurationValue(FaxClientSpiConfigurationConstants.SUBMIT_FAX_JOB_COMMAND_PROPERTY_KEY);
          if(this.submitCommand==null)
          {
              this.submitCommand=FaxClientSpiConfigurationConstants.SUBMIT_FAX_JOB_COMMAND_DEFAULT_VALUE.toString();
          }
          this.printQueueParameter=this.getConfigurationValue(FaxClientSpiConfigurationConstants.PRINT_QUEUE_PARAMETER_PROPERTY_KEY);
          if(this.printQueueParameter==null)
          {
              this.printQueueParameter=FaxClientSpiConfigurationConstants.PRINT_QUEUE_PARAMETER_DEFAULT_VALUE.toString();
          }
          this.printQueueName=this.getConfigurationValue(FaxClientSpiConfigurationConstants.PRINT_QUEUE_NAME_PROPERTY_KEY);
          if(this.printQueueName==null)
          {
              throw new FaxException("Print queue name not defined in fax4j.properties. Property: "+FaxClientSpiConfigurationConstants.PRINT_QUEUE_NAME_PROPERTY_KEY);
          }
          this.generalParameters=this.getConfigurationValue(FaxClientSpiConfigurationConstants.GENERAL_PARAMETERS_PROPERTY_KEY);
          if(this.generalParameters==null)
          {
              this.generalParameters=FaxClientSpiConfigurationConstants.GENERAL_PARAMETERS_DEFAULT_VALUE.toString();
          }
          this.phoneParameter=this.getConfigurationValue(FaxClientSpiConfigurationConstants.PHONE_PARAMETER_PROPERTY_KEY);
          if(this.phoneParameter==null)
          {
              this.phoneParameter=FaxClientSpiConfigurationConstants.PHONE_PARAMETER_DEFAULT_VALUE.toString();
          }
          this.faxToParameter=this.getConfigurationValue(FaxClientSpiConfigurationConstants.FAX_TO_PARAMETER_PROPERTY_KEY);
          if(this.faxToParameter==null)
          {
              this.faxToParameter=FaxClientSpiConfigurationConstants.FAX_TO_PARAMETER_DEFAULT_VALUE.toString();
          }
          
          //init process output validator
          this.processOutputValidator=this.createMacProcessOutputValidator();
      }
docs: This function initializes the fax client SPI.