i need solution use Memento Design Pattern.

Describing Design Patterns: . Pattern Name and Classification Intent A short statement that answers the following questions: What does the design pattern do? What is its rationale and intent? What particular design issue or problem does it address? Also Known As Other well-known names for the pattern, if any . Motivation A scenario that illustrates a design problem and how the class and object structures in the pattern solve the problem. The scenario will help you understand the more abstract description of the pattem that follows. Applicability What are the situations in which the design pattern can be applied? What are examples of poor designs that the pattem can address? How can you recognize these situations? . Structure A graphical representation of the classes in the pattern. . Consequences How does the pattern support its objectives? What are the trade-offs and results of using the pattern? What aspect of system structure does it let you vary independently? Implementation What pilfalls, hints, or techniques should you be aware of when implementing the pattern? Are there language-specific issues? Sample Code (optional) Code fragments that illustrate how you might implement the pattern. known Uses Examples of the pattern found in real systems. We include at least two examples from different domains. Related Patterns What design patterns are closely related to this one? What are the important differences? With which other patterns should this one be used? Describing Design Patterns: . Pattern Name and Classification Intent A short statement that answers the following questions: What does the design pattern do? What is its rationale and intent? What particular design issue or problem does it address? Also Known As Other well-known names for the pattern, if any . Motivation A scenario that illustrates a design problem and how the class and object structures in the pattern solve the problem. The scenario will help you understand the more abstract description of the pattem that follows. Applicability What are the situations in which the design pattern can be applied? What are examples of poor designs that the pattem can address? How can you recognize these situations? . Structure A graphical representation of the classes in the pattern. . Consequences How does the pattern support its objectives? What are the trade-offs and results of using the pattern? What aspect of system structure does it let you vary independently? Implementation What pilfalls, hints, or techniques should you be aware of when implementing the pattern? Are there language-specific issues? Sample Code (optional) Code fragments that illustrate how you might implement the pattern. known Uses Examples of the pattern found in real systems. We include at least two examples from different domains. Related Patterns What design patterns are closely related to this one? What are the important differences? With which other patterns should this one be used