Interfaces and templates

[JN via Digitalmars-d-learn]

import std.stdio;

interface IWriter
{
    void write(U)(U x);
}
class Foo : IWriter
{
    void write(U)(U x, int y)
    {
        writeln(x);
    }
}



void main()
{
}

Does this code make sense? If so, why doesn't it throw an error 
about unimplemented write (or incorrectly implemented) method?