c# .net core entity framework one to many

protected override void OnModelCreating(Modelbuilder modelBuilder)
{
    modelBuilder.Entity<Employee>()
        .HasOne(e => e.Company)
        .WithMany(c => c.Employees);
}

protected override void OnModelCreating(Modelbuilder modelBuilder)
{
    modelBuilder.Entity<Company>()
        .HasMany(c => c.Employees)
        .WithOne(e => e.Company);
}

public class Company
{
    public int Id { get; set; }
    public string Name { get; set; }
    public ICollection<Employee> Employees { get; set; }
}
public class Employee
{
    public int Id { get; set; }
    public string Name { get; set; }
    public Company Company { get; set; }
}