The user-supplied instance identifier. If this parameter is specified, information from only the specific DB instance is returned. This
            parameter isn't case sensitive. Constraints: 
- Must contain from 1 to 63 alphanumeric characters or hyphens
- First character must be a letter
- Cannot end with a hyphen or contain two consecutive hyphens
 Declaration Syntax
 Declaration Syntax| C# | 
public string DBInstanceIdentifier { get; set; }