getAdapter (name) {
    this.dbg('getAdapter', 'name:', name)
    const adapter = this.getAdapterName(name)
    if (!adapter) {
      throw utils.err(`${DOMAIN}#getAdapter`, 'name')(400, 'string', name)
    }
    return this.getAdapters()[adapter]
  }
Return the registered adapter with the given name or the default adapter if
no name is provided.

@method Mapper#getAdapter
@param {string} [name] The name of the adapter to retrieve.
@returns {Adapter} The adapter.
@since 3.0.0
@tutorial ["http://www.js-data.io/v3.0/docs/connecting-to-a-data-source","Connecting to a data source"]