code: def matrix_undirected_unweighted(user):
      
      matrix = matrix_undirected_weighted(user, interaction=None)
      for a, b in combinations(range(len(matrix)), 2):
          if matrix[a][b] is None or matrix[b][a] is None:
              continue
  
          if matrix[a][b] > 0 and matrix[b][a] > 0:
              matrix[a][b], matrix[b][a] = 1, 1
  
      return matrix
docs: Returns an undirected, unweighted matrix where an edge exists if the
      relationship is reciprocated.