public async Task<BoxRetentionPolicyAssignment> CreateRetentionPolicyAssignmentAsync(BoxRetentionPolicyAssignmentRequest policyAssignmentRequest, List<string> fields = null)
{
BoxRequest request = new BoxRequest(_config.RetentionPolicyAssignmentsUri)
.Method(RequestMethod.Post)
.Param(ParamFields, fields)
.Payload(_converter.Serialize<BoxRetentionPolicyAssignmentRequest>(policyAssignmentRequest));
IBoxResponse<BoxRetentionPolicyAssignment> response = await ToResponseAsync<BoxRetentionPolicyAssignment>(request).ConfigureAwait(false);
return response.ResponseObject;
}