code: function UdfJob (client, udfModule, command) {
    this.client = client
    this.udfModule = udfModule
    this.command = command
  }
docs: @class UdfJob
  @classdesc Job class for waiting for UDF module registration/deregistration
  to complete across an entire Aerospike cluster.
  @extends Job
  
  @see {@link Client#udfRegister}
  @see {@link Client#udfRemove}
  
  @example
  
  const Aerospike = require('aerospike')
  
  let path = './udf/my_module.lua'
  
  Aerospike.connect()
  .then(client => {
  client.udfRegister(path)
  .then(job => job.wait())
  .then(() => {
  console.info('UDF module %s was registered successfully', path)
  client.close()
  })
  .catch(error => {
  console.error('Error registering UDF module:', error)
  client.close()
  })
  })
  .catch(error => console.error('Error connecting to cluster:',  error))