Cast Entity to Implemented Interface in a Generic Method Using LINQ for Entity Framework

Question

I have a generic method to query objects of type TEntity in EF. I Want to add a condition as a where clause if TEntity implements a specific interface. The method I have is:

Answer 1

This is a working solution:

public TEntity GetByUserID(Guid userID, params Include[] includes)
{
    var query = this.DbSet;
    query = Where(query, x => !x.IsDeleted);
    return query
        .FirstOrDefault(x => x.UserID == userID);
}

public static IQueryable Where(IQueryable query, Expression> predicate)
{
    if (typeof(TEntity).IsImplementationOf())
    {
        query = ((IQueryable)query)
            .Where(predicate)
            .Cast();
    }
    return query;
}