初始化模式?

假设我有A级:

public class A
{
  private B _b;

  public class A(B b)
  {
    Assert.That(b != null);
    _b = b;
  }
}

对象b需要一些复杂的初始化,比如:

b.Prop1 = ...
b.Prop2 = ...
b.Prop3 = ...

int answerToSomeComplexFormula = PerformComplexFormula();

b.Prop4 = answerToSomeCopmlexFormula

etc...

我不想在构造函数中执行此初始化。是否有某种模式的名称来描述返回具有复杂初始化的对象?类似于:

public class BInitializer
{
   public B Create()
   {
      B b = new B();
      // set up properties
      return b;
   }
}

BInitializer initializer = new BInitializer();
B b = initializer.Create();

A a = new A(b)

谢谢