GetPermissionsForUserInDomain throws 'Sequence has no elements' when domain does not exist (EF Core Adapter)

[Raja-Rajasekaran]

Description

When calling enforcer.GetPermissionsForUserInDomain(user, domain) using Casbin.NET with the EF Core Adapter, an exception is thrown if the specified domain does not exist in the casbin_rule table.

Steps to Reproduce:

1. Use Casbin.NET with the EF Core Adapter.
2. Call enforcer.GetPermissionsForUserInDomain("someuser", "nonexistent-domain") where "nonexistent-domain" does not exist in the casbin_rule table.
3. Observe that a System.InvalidOperationException: Sequence contains no elements is thrown.

Expected Behavior:

The method should return an empty list/array when no permissions are found for the user in the specified domain, instead of throwing an exception.

Actual Behavior:

A System.InvalidOperationException is thrown with the message:
Sequence contains no elements

Environment:

Casbin.NET version: 2.12.0
EF Core Adapter version: 2.7.0
.NET version: net9.0
Database: SQL Server

rbac_with_domains.conf:

[request_definition]
r = sub, dom, obj, act

[policy_definition]
p = sub, dom, obj, act 

[role_definition]
g = _, _, _

[policy_effect]
e = some(where (p.eft == allow))

[matchers]  
m = g(r.sub, p.sub, r.dom) && keyMatch(r.dom, p.dom) && regexMatch(r.obj, p.obj) && regexMatch(r.act, p.act)

Policy

Id	PType	V0	V1	V2	V3	V4	V5
1	p	my-app-admin	my-domain	/*	read
2	g	user_1@email.com	my-app-admin	my-domain

Additional Context:

This issue makes it difficult to safely query permissions for data that may not exist. A workaround is to catch the exception, but ideally the method should return an empty result.