code: def density(creation_sequence):
      """
      Return the density of the graph with this creation_sequence.
      The density is the fraction of possible edges present.
      """
      N = len(creation_sequence)
      two_size = sum(degree_sequence(creation_sequence))
      two_possible = N * (N - 1)
      den = two_size / two_possible
      return den
  
imports: from math import sqrt
  import networkx
  from networkx.utils import py_random_state
label_desc: Use image node_id 16 for calling a global function with example usage: density(creation_sequence) and returns: den