# File lib/bundler/vendor/molinillo/lib/molinillo/dependency_graph.rb, line 125
    def detach_vertex_named(name)
      vertex = vertex_named(name)
      return unless vertex
      successors = vertex.successors
      vertices.delete(name)
      edges.reject! { |e| e.origin == vertex || e.destination == vertex }
      successors.each { |v| detach_vertex_named(v.name) unless root_vertices[v.name] || v.predecessors.any? }
    end