I'd like to write a sketch which does depend on a file from the SD card in an Ethernet shield v2. As I cannot use the shield at the moment I'd like to write and run the code on the Arduino only. This requires that I can use a fake file instead of the actual one read from the SD card. The machanism I need to use is mock/fake object.
How can I fake a file comparable to I'd do in a non-embedded environment?