```ruby
require 'simple-graph'

require "directed_graph/version"
require_relative "./directed_graph/job_runner.rb"
require_relative "./directed_graph/vertex.rb"
require_relative "./directed_graph/edge.rb"
require_relative "./directed_graph/graph.rb"
require_relative "./directed_graph/graph_builder.rb"

module DirectedGraph
end
```

Remove the line that was loading graph_builder
user
```ruby
require 'simple-graph'

require "directed_graph/version"
require_relative "./directed_graph/job_runner.rb"
require_relative "./directed_graph/vertex.rb"
require_relative "./directed_graph/edge.rb"
require_relative "./directed_graph/graph.rb"

module DirectedGraph
end
```
assistant