src/engine/parents.js
function parents (pipe, taskKey) {
  var inputPipesOf = inputPipes.bind(null, pipe)
  var parentTaskIds = []

  function pushParentTaskId (pipe) {
    parentTaskIds.push(pipe[0])
  }

  inputPipesOf(taskKey).forEach(pushParentTaskId)

  return parentTaskIds
}
function parents (pipe, taskKey) {
  var inputPipesOf = inputPipes.bind(null, pipe)
  var parentTaskIds = []

  function pushParentTaskId (pipe) {
    parentTaskIds.push(pipe[0])
  }

  inputPipesOf(taskKey).forEach(pushParentTaskId)

  return parentTaskIds
}
function parents ( pipe , taskKey ) { var inputPipesOf = inputPipes . bind ( null , pipe ) var parentTaskIds = [ ] function pushParentTaskId ( pipe ) { parentTaskIds . push ( pipe [ 0 ] ) } inputPipesOf ( taskKey ) . forEach ( pushParentTaskId ) return parentTaskIds }
Compute parent tasks.

@param {Array} pipes of graph
@param {String} taskKey

@returns {Array} parentTaskIds
Compute parent tasks .