Just remove e so the signature is function ().

I like these "documentation" parameters, but enabling this rule caught at least a handful of real errors (variables which were declared/assigned but not used) and getting those actual issues cleaned up seemed worth getting yelled at about these sort-of-nice-to-have-but-not-technically-necessary parameters.

Ideally we'd detect the other stuff but ignore these, but we'd have to fork jshint to support that.

Or maybe add e.kill(), it seems like we should be swallowing these events? Maybe like:

if (this._depth) {
  e.kill();
  this._updateDepth(...);
}