/// <summary>
/// Adds a relationship between two digital twins.
/// Status codes:
/// 200 (OK): Success.
/// 400 (Bad Request): The request is invalid.
/// 404 (Not Found): There is either no digital twin, target digital twin, or
/// relationship with the provided id.
/// 409 (Conflict): A relationship with the provided id already exists.
/// </summary>
/// <param name='operations'>
/// The operations group for this extension method.
/// </param>
/// <param name='id'>
/// The id of the digital twin. The id is unique within the service and case
/// sensitive.
/// </param>
/// <param name='relationshipId'>
/// The id of the relationship. The id is unique within the digital twin and
/// case sensitive.
/// </param>
/// <param name='relationship'>
/// The data for the relationship.
/// </param>
/// <param name='ifNoneMatch'>
/// Only perform the operation if the entity does not already exist. Possible
/// values include: '*'
/// </param>
public static object AddRelationship(this IDigitalTwinsOperations operations, string id, string relationshipId, object relationship = default(object), string ifNoneMatch = default(string))
{
return(operations.AddRelationshipAsync(id, relationshipId, relationship, ifNoneMatch).GetAwaiter().GetResult());
}