Structure containing the updated stack policy body. If you pass StackPolicyBody and StackPolicyURL, only
            StackPolicyBody is used. If you want to update a stack policy during a stack update, specify an updated stack policy. For example,
            you can include an updated stack policy to protect a new resource created in the stack update. If you do not specify a stack policy, the
            current policy that is associated with the stack is unchanged.
             
            
Constraints:
 Declaration Syntax
 Declaration Syntax| C# | 
public string StackPolicyBody { get; set; }