+sub may_employee_view_project_invoices {
+  my ($self, $employee) = @_;
+
+  return undef if !$self->id;
+
+  my $employee_id = ref($employee) ? $employee->id : $employee * 1;
+  my $query       = <<EOSQL;
+    SELECT project_id
+    FROM employee_project_invoices
+    WHERE (employee_id = ?)
+      AND (project_id  = ?)
+    LIMIT 1
+EOSQL
+
+  return !!$self->db->dbh->selectrow_arrayref($query, undef, $employee_id, $self->id)->[0];
+}
+