code: function numberOfNonSelfLinkingCycles (node, id) {
      var sourceCount = 0
      node.sourceLinks.forEach(function (l) {
        sourceCount = l.circular && !selfLinking(l, id)
          ? sourceCount + 1
          : sourceCount
      })
  
      var targetCount = 0
      node.targetLinks.forEach(function (l) {
        targetCount = l.circular && !selfLinking(l, id)
          ? targetCount + 1
          : targetCount
      })
  
      return sourceCount + targetCount
    }
docs: Return the number of circular links for node, not including self linking links