问题 How do I query Azure AD Graph for a SignInName? i.e. I want to take the user's login-name and find the user object in the Azure AD Graph. I would assume I'm supposed to use $filter, right? I tried: https://graph.windows.net/myB2Ctenant.onmicrosoft.com/users?api-version=1.6&$filter=signInNames eq spottedmahn and I got: The operand for a binary operator 'Equal' is not a single value. Binary operators require both operands to be single values. Ok, so maybe I'm suppoed to use the any operator so