code: function forwardCurrentToHead(analyzer, node) {
      const codePath = analyzer.codePath
      const state = CodePath.getState(codePath)
      const currentSegments = state.currentSegments
      const headSegments = state.headSegments
      const end = Math.max(currentSegments.length, headSegments.length)
      let i = 0
      let currentSegment = null
      let headSegment = null
  
      // Fires leaving events.
      for (i = 0; i < end; ++i) {
          currentSegment = currentSegments[i]
          headSegment = headSegments[i]
  
          if (currentSegment !== headSegment && currentSegment) {
              if (currentSegment.reachable) {
                  analyzer.emitter.emit(
                      "onCodePathSegmentEnd",
                      currentSegment,
                      node
                  )
              }
          }
      }
  
      // Update state.
      state.currentSegments = headSegments
  
      // Fires entering events.
      for (i = 0; i < end; ++i) {
          currentSegment = currentSegments[i]
          headSegment = headSegments[i]
  
          if (currentSegment !== headSegment && headSegment) {
              CodePathSegment.markUsed(headSegment)
              if (headSegment.reachable) {
                  analyzer.emitter.emit(
                      "onCodePathSegmentStart",
                      headSegment,
                      node
                  )
              }
          }
      }
  }
docs: /* istanbul ignore next 
  Copied from https://github.com/eslint/eslint/blob/16fad5880bb70e9dddbeab8ed0f425ae51f5841f/lib/code-path-analysis/code-path-analyzer.js#L137
  
  @param {CodePathAnalyzer} analyzer - The instance.
  @param {ASTNode} node - The current AST node.
  @returns {void}