title: Eloquent hasOne vs belongsTo degenerate to same function if both keys are specified?
body: <p>For the case of a one-to-one relationship, if I fully specify the keys in the method calls, is there a difference between <code>hasOne</code> and <code>belongsTo</code> relationships? Or, asked differently, if I used <code>hasOne</code> on both sides of the relation, would it be the same result?</p>