Let's say I have three packages A, B, and C. All of them have a function with the same name filter but with different functionalities. I tend to use all these 3 packages in my work, and sometimes I couldn't remember the warning message about overriding. So if I use the function filter, how can I know which package it is from. I understand that can use A::filter, B::filter, or C::filter, but I want to know if my desired filter function is being used ex ante.