```ruby
#! /usr/bin/env ruby

# Note: This assumes we're running from the root of the stash-harvester project
$LOAD_PATH << File.dirname(__FILE__)
require 'lib/stash/harvester'

list_records_config = Stash::Harvester::OAIPMH::OAIConfig.new(
  oai_base_url: 'http://oai.datacite.org/oai',
  metadata_prefix: 'oai_datacite',
  set: 'REFQUALITY'
)

list_records_task = Stash::Harvester::OAIPMH::ListRecordsTask.new(
  config: list_records_config,
  from_time: Time.utc(2013, 6, 1),
  until_time: Time.utc(2013, 6, 30)
)

response = list_records_task.harvest_records
response.each do |record|
  puts record.identifier
end
```

Rename variable to match class name
user
```ruby
#! /usr/bin/env ruby

# Note: This assumes we're running from the root of the stash-harvester project
$LOAD_PATH << File.dirname(__FILE__)
require 'lib/stash/harvester'

oai_config = Stash::Harvester::OAIPMH::OAIConfig.new(
  oai_base_url: 'http://oai.datacite.org/oai',
  metadata_prefix: 'oai_datacite',
  set: 'REFQUALITY'
)

list_records_task = Stash::Harvester::OAIPMH::ListRecordsTask.new(
  config: oai_config,
  from_time: Time.utc(2013, 6, 1),
  until_time: Time.utc(2013, 6, 30)
)

response = list_records_task.harvest_records
response.each do |record|
  puts record.identifier
end
```
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