code: def is_edge_cover(G, cover):
      """Decides whether a set of edges is a valid edge cover of the graph.
  
      Given a set of edges, whether it is an edge covering can
      be decided if we just check whether all nodes of the graph
      has an edge from the set, incident on it.
  
      Parameters
      ----------
      G : NetworkX graph
          An undirected bipartite graph.
  
      cover : set
          Set of edges to be checked.
  
      Returns
      -------
      bool
          Whether the set of edges is a valid edge cover of the graph.
  
      Examples
      --------
      >>> G = nx.Graph([(0, 1), (0, 2), (0, 3), (1, 2), (1, 3)])
      >>> cover = {(2, 1), (3, 0)}
      >>> nx.is_edge_cover(G, cover)
      True
  
      Notes
      -----
      An edge cover of a graph is a set of edges such that every node of
      the graph is incident to at least one edge of the set.
      """
      return set(G) <= set(chain.from_iterable(cover))
  
imports: from functools import partial
  from itertools import chain
  import networkx
  from networkx.utils import arbitrary_element, not_implemented_for
label_desc: Use image node_id 2 for calling a global function with example usage: is_edge_cover(G, cover) and returns: unknown