Gets and sets the property MasterUsername. 
            
The user name associated with the master user account for the cluster that is being created.
Constraints:
- Must be 1 - 128 alphanumeric characters.
- First character must be a letter.
- Cannot be a reserved word. A list of reserved words can be found in Reserved Words in the Amazon Redshift Database Developer Guide.
 Declaration Syntax
 Declaration Syntax| C# | 
public string MasterUsername { get; set; }