checkNonNegative(--edgeCount);
    }
    return previousValue;
  }

  @Override
  @CanIgnoreReturnValue
  @CheckForNull
  public V removeEdge(EndpointPair<N> endpoints) {
    validateEndpoints(endpoints);
    return removeEdge(endpoints.nodeU(), endpoints.nodeV());
  }

  private GraphConnections<N, V> newConnections() {
    return isDirected()

      checkNonNegative(--edgeCount);
    }
    return previousValue;
  }

  @Override
  @CanIgnoreReturnValue
  @CheckForNull
  public V removeEdge(EndpointPair<N> endpoints) {
    validateEndpoints(endpoints);
    return removeEdge(endpoints.nodeU(), endpoints.nodeV());
  }

  private GraphConnections<N, V> newConnections() {
    return isDirected()

        if (cycle != null) {
            // remove edge which introduced cycle
            removeEdge(from, to);
            throw new CycleDetectedException(
                    "Edge between '" + from.label + "' and '" + to.label + "' introduces to cycle in the graph", cycle);
        }
    }

    void removeEdge(Vertex from, Vertex to) {
        from.children.remove(to);
        to.parents.remove(from);
    }

        if (cycle != null) {
            // remove edge which introduced cycle
            removeEdge(from, to);
            throw new CycleDetectedException(
                    "Edge between '" + from.label + "' and '" + to.label + "' introduces to cycle in the graph", cycle);
        }
    }

    void removeEdge(Vertex from, Vertex to) {
        from.children.remove(to);
        to.parents.remove(from);
    }

		for i := 0; i < len(b.Succs); {
			e := b.Succs[i]
			if reachable[e.b.ID] {
				b.removeEdge(i)
			} else {
				i++
			}
		}
	}

	// Get rid of dead edges from live code.
	for _, b := range f.Blocks {
		if !reachable[b.ID] {
			continue
		}
		if b.Kind != BlockFirst {
			continue
		}
		b.removeEdge(1)
		b.Kind = BlockPlain
		b.Likely = BranchUnknown
	}

          back_edges_.push_back(
              BackEdge{e, e->src(), e->src_output(), e->dst(), e->dst_input()});
        }
      }
    }
  }
  for (const BackEdge& be : back_edges_) {
    graph_->RemoveEdge(be.edge);
  }
  return absl::OkStatus();
}

const std::vector<BackEdgeHelper::BackEdge>& BackEdgeHelper::RemovedEdges()
    const {
  return back_edges_;
}

Status BackEdgeHelper::Replace() {

			return false
		}
	}

	// We do not need to redirect the Preds of s0 and s1 to ss,
	// the following optimization will do this.
	b.removeEdge(0)
	if s0 != b && len(s0.Preds) == 0 {
		s0.removeEdge(0)
		// Move any (dead) values in s0 to b,
		// where they will be eliminated by the next deadcode pass.
		for _, v := range s0.Values {
			v.Block = b
		}

		v := b.NewValue0(bc.Pos, op, bc.Type)
		v.AddArg(pc)
		v.AddArg(bc)

		// Set the combined control value as the control value for b.
		b.SetControl(v)

		// Modify p so that it jumps directly to b.
		p.removeEdge(i)
		p.Kind = BlockPlain
		p.Likely = BranchUnknown
		p.ResetControls()

		return true
	}

	// TODO: could negate condition(s) to merge controls.
	return false
}

        TF_RET_CHECK(e->src_output() == 0)
            << "expected constant to have exactly one non-control output, but "
               "found output index = "
            << e->src_output();
        graph_->RemoveEdge(e);
        graph_->AddEdge(input_cloned, 0, n, dst_input);
      }
    }
  }
  return absl::OkStatus();
}

Status CloneConstantsForBetterClusteringPassImpl::Run() {