# graph module
module Graph

  # graph.rb
  #
  # a class that represents a graph
  class Graph
  
    attr_accessor :name, :nodes
    def initialize(name)
      @name = name
      @nodes = [] # empty list of nodes
    end

    # add a node to the graph with the given value
    def add(value)
      @nodes << Node.new(value)
    end

    # add the given node to the graph
    def add_node(node)
      @nodes << node
    end

    # add the array of nodes to the graph
    def add_nodes(node_array)
      @nodes += node_array
    end
  
  end
  
  
  # node
  #
  # a class that represents a node in a graph
  class Node
  
    attr_accessor :value, :incoming, :outgoing
    def initialize(value)
      @value = value
      @incoming = []
      @outgoing = []
    end
  
  end

end

# graph module
module Graph

  # graph.rb
  #
  # a class that represents a graph
  class Graph
  
    attr_accessor :name, :nodes
    def initialize(name)
      @name = name
      @nodes = [] # empty list of nodes
    end

    # add a node to the graph with the given value
    def add(value)
      @nodes << Node.new(value)
    end

    # add the given node to the graph
    def add_node(node)
      @nodes << node
    end

    # add the array of nodes to the graph
    def add_nodes(node_array)
      @nodes += node_array
    end

    # remove the given node from the graph
    def remove_node(node)
      @nodes.delete(node)
      # the edges/vertices are going to have to be handled too
    end
  
  end
  
  
  # node
  #
  # a class that represents a node in a graph
  class Node
  
    attr_accessor :value, :incoming, :outgoing
    def initialize(value)
      @value = value
      @incoming = []
      @outgoing = []
    end
  
  end

end

Add an implementation of the remove_node method, it passes the space. The functionality that is still missing though is dealing with the vertices.
Add an implementation of the remove_node method, it passes the space. The
functionality that is still missing though is dealing with the vertices.
