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

@param {Model} model
@param {Schema} schema