Question on keyword "with"

Hi guys.

First of all, thanks for the wonderful plugin. It is helping me a lot in my work. But in the process, I have noticed that intellij does not recognize types created with the keyword "with". For instance, suppose there are two traits A and B. Then, we can set an argument of a function foo as follows

def foo(arg: A with B)

But in the function, I cannot access the functions of A and B. Also, for a normal function bar

def foo(arg: A)

Calling it as follows draws a red line saying that the type does not match.

val temp: A with B = someFunction
foo(temp)

Is this intentional in preventing some bugs? My code compiles using an external compiler in the terminal without any errors or warnings.

Thanks a lot