lib/Model.js
function (model, schema) {
  debug('applying statics');
  for (const i in schema.statics) {
    model[i] = schema.statics[i].bind(model);
  }
}
function (model, schema) {
  debug('applying statics');
  for (const i in schema.statics) {
    model[i] = schema.statics[i].bind(model);
  }
}
/*!
Register statics for this model
@param {Model} model
@param {Schema} schema