The class for all errors raised by the SDK.
An error code associated to the error. For HTTP related errors, this will be the HTTP response code returned by the server. For example, if retrieving of a virtual machine fails because it doesn't exist this attribute will contain the integer value 404. Note that this may be `nil` if the error is not HTTP related.
@return [Integer] The HTTP error code.
The `Fault` object associated to the error.
@return [Fault] The fault object associated to the error, if a fault was provided by the server, `nil` otherwise.