createBranch API params #1549

The API in the documentation for Repository.createBranch is written as : repository.createBranch(name, commit, force)

But in the example over here: https://github.com/nodegit/nodegit/blob/master/examples/create-branch.js, it is used as:

return repo.createBranch(
  "new-branch",
  commit,
  0,
  repo.defaultSignature(),
  "Created new-branch on HEAD");

What are the 4th and 5th parameters given to the function? Am I missing something / looking at the wrong documentation or example?