private static void GenerateRequestModelDescription(
            HelpPageApiModel apiModel, 
            ModelDescriptionGenerator modelGenerator, 
            HelpPageSampleGenerator sampleGenerator)
        {
            var apiDescription = apiModel.ApiDescription;
            foreach (var apiParameter in apiDescription.ParameterDescriptions)
            {
                if (apiParameter.Source == ApiParameterSource.FromBody)
                {
                    var parameterType = apiParameter.ParameterDescriptor.ParameterType;
                    apiModel.RequestModelDescription = modelGenerator.GetOrCreateModelDescription(parameterType);
                    apiModel.RequestDocumentation = apiParameter.Documentation;
                }
                else if (apiParameter.ParameterDescriptor != null
                         && apiParameter.ParameterDescriptor.ParameterType == typeof(HttpRequestMessage))
                {
                    var parameterType = sampleGenerator.ResolveHttpRequestMessageType(apiDescription);

                    if (parameterType != null)
                    {
                        apiModel.RequestModelDescription = modelGenerator.GetOrCreateModelDescription(parameterType);
                    }
                }
            }
        }