In Drupal 8, I have a custom entity 'Data' with bundles enabled. I created two new bundle (Data Types) called 'Big Data' and 'Small Data'. I add a textfield to 'Big Data' and a textarea to 'Small Data' via 'manage fields'.
In a new custom Form class I want to get form elements for both the textfield of Big Data as the textarea of Small Data.
How can I achieve this without loading the complete form of each bundle and adding only the needed form element to my custom form object?