I can't import any class or packages and I also have to use the instance variable istream to read from the file.

Write a Java method readFile() that reads values from a file and prints the values each in its own line on the console. In Coderunner the file is hidden from you and is instead made available to you via an inputstream object referenced by the istream instance variable in the class in which your method will be placed. The file contains two integer values and a double value, in that order. Use the istream object instead of Files.newinputstream(Paths.get("...")), to read from the file. For example