==== Source: A ====
pragma experimental ABIEncoderV2;

struct Data {
    bool flag;
}

contract A {
    function get() public view returns (Data memory) {}
}

contract B {
    modifier validate() virtual {
        A(0x00).get();
        _;
    }
}

==== Source: B ====
import "A";

contract C is B {
    function foo() public pure validate {}

    modifier validate() override {
        _;
    }
}
// ----