Невозможно преобразовать объект задачи в задачу SqlDataReader

Question

Я создаю простой класс, но получаю Cannot convert Task object to Task SqlDataReader. Вот мой код,

public static class SqlHelper 
{ 
    enum ExecutionType 
    { 
     NonQuery, 
     Reader, 
     Scaler 

    } 
    public static async Task<int> ExecuteNonQueryAsync(string connectionString, CommandType commandType, 
     string commandText, 
     params SqlParameter[] parameters) 
    { 
     return (Task<int>)ExecuteAsync(ExecutionType.NonQuery, connectionString, commandType, commandText, parameters); 
    } 


    public static async Task<SqlDataReader> ExecuteReaderAsync(string connectionString, CommandType commandType, 
     string commandText, params SqlParameter[] parameters) 
    { 
     return (Task<SqlDataReader>)ExecuteAsync(ExecutionType.Reader, connectionString, commandType, commandText, parameters); 
    } 

    public static async Task<object> ExecuteScalarAsync(string connectionString, CommandType commandType, string commandText, 
     params SqlParameter[] parameters) 
    { 
     return ExecuteAsync(ExecutionType.Scaler, connectionString, commandType, commandText, parameters); 
    } 


    private static async Task<object> ExecuteAsync(ExecutionType executionType, string connectionString, CommandType commandType, string commandText, 
     params SqlParameter[] parameters) 
    { 
     using (var connection = new SqlConnection(connectionString)) 
     { 
      using (var command = new SqlCommand(commandText, connection) { CommandType = commandType }) 
      { 
       command.Parameters.AddRange(parameters); 
       await connection.OpenAsync(); 
       if (executionType == ExecutionType.Reader) 
       { 
        return await command.ExecuteReaderAsync(); 
       } 
       if (executionType == ExecutionType.NonQuery) 
       { 
        return await command.ExecuteNonQueryAsync(); 
       } 
       return await command.ExecuteScalarAsync(); 
      } 
     } 
    }   
} 

Любое предложение исправить эту проблему будет оценено по достоинству?