<｜begin▁of▁sentence｜>### Instruction:
Given a directed graph with nodes 0, 1, 2, and 3 and directed edges from 0 to 1, 1 to 2, and 2 to 3, how can we calculate and access the number of 'mutual', 'asymmetric', and 'null' dyads (pair of nodes) present in the graph using NetworkX?
### Response:
from networkx import DiGraph
from networkx.algorithms.structuralholes import dyad_census

# Create a directed graph with some edges
G = DiGraph([(0, 1), (1, 2), (2, 3)])

# Perform a dyad census
#census = DyadCensus(G)  # Assuming DyadCensus is correctly imported, which is not the case here
#dyad_types = census['mutual']  # Access the number of mutual relationships

dyad_types = dyad_census(G)  # Using the NetworkX API instead
print(dyad_types)
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