```ruby
require 'rubygems'
require 'bundler/setup'

ENV['RACK_ENV'] = 'test'

require 'knockoff'

ActiveRecord::Base.configurations = {
  'test' => { 'adapter' => 'sqlite3', 'database' => 'tmp/test_db' }
}

# Setup the ENV's for replicas
ENV['KNOCKOFF_REPLICA1'] = 'sqlite3:tmp/test_replica_db'
ENV['KNOCKOFF_REPLICA_ENVS'] = 'KNOCKOFF_REPLICA1'

# Prepare databases
class User < ActiveRecord::Base
end

# Create two records on master
ActiveRecord::Base.establish_connection(:test)
ActiveRecord::Base.connection.create_table :users, force: true
User.create
User.create

# Create one record on slave, emulating replication lag
ActiveRecord::Base.establish_connection(ENV['KNOCKOFF_REPLICA1'])
ActiveRecord::Base.connection.create_table :users, force: true
User.create

# Reconnect to master
ActiveRecord::Base.establish_connection(:test)```

Use symbols in the configuration hash
user
```ruby
require 'rubygems'
require 'bundler/setup'

ENV['RACK_ENV'] = 'test'

require 'knockoff'

ActiveRecord::Base.configurations = {
  test: {
    adapter: 'sqlite3',
    database: 'tmp/test_db'
  }
}

# Setup the ENV's for replicas
ENV['KNOCKOFF_REPLICA1'] = 'sqlite3:tmp/test_replica_db'
ENV['KNOCKOFF_REPLICA_ENVS'] = 'KNOCKOFF_REPLICA1'

# Prepare databases
class User < ActiveRecord::Base
end

# Create two records on master
ActiveRecord::Base.establish_connection(:test)
ActiveRecord::Base.connection.create_table :users, force: true
User.create
User.create

# Create one record on slave, emulating replication lag
ActiveRecord::Base.establish_connection(ENV['KNOCKOFF_REPLICA1'])
ActiveRecord::Base.connection.create_table :users, force: true
User.create

# Reconnect to master
ActiveRecord::Base.establish_connection(:test)```
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