The Builder design pattern provides a solution:
Encapsulate creating and assembling the parts of a complex object in a separate Builder object.
A class delegates object creation to a Builder object
instead of instantiating concrete classes directly.
Describing the Builder design in more detail is the theme of the following sections.
See Applicability section for all problems Builder can solve.

• The key idea in this pattern is to separate creating and assembling the parts of a complex object from other (construction) code (Director).
• Define separate Builder objects:
  • Define an interface for creating parts of a complex object (Builder | buildPartA(),buildPartB(),…).
  • Define classes (Builder1,…) that implement the interface.
    The object is created step by step to have finer control over the creation process.
• This enables compile-time flexibility (via inheritance).
  The way the parts of a complex object are created and assembled can be implemented and changed independently by defining new (sub)classes.
• A class (Director) delegates the responsibility for creating and assembling the parts of a com­plex object to a Builder object (builder.buildPartA(),builder.buildPartB(),…).
• This enables run-time flexibility (via object composition).
  A class (the same construction process) can use different Builder objects to create different representations of a complex object.