lib/aerospike/client.rb
def append(key, bins, options = nil)
      policy = create_policy(options, WritePolicy, default_write_policy)
      command = WriteCommand.new(@cluster, policy, key, hash_to_bins(bins), Aerospike::Operation::APPEND)
      execute_command(command)
    end
def append(key, bins, options = nil)
      policy = create_policy(options, WritePolicy, default_write_policy)
      command = WriteCommand.new(@cluster, policy, key, hash_to_bins(bins), Aerospike::Operation::APPEND)
      execute_command(command)
    end
-------------------------------------------------------
 Operations string
-------------------------------------------------------

  Appends bin values string to existing record bin values.
  The policy specifies the transaction timeout, record expiration and
  how the transaction is handled when the record already exists.

  This call only works for string values.

  If no policy options are provided, +@default_write_policy+ will be used.
  Examples:

  client.append key, {'bin', 'value to append'}, :timeout => 0.001