A class for implementing a Signature Method See section 9 ("Signing Requests") in the spec

### Methods

## Build up the signature NOTE: The output of this function MUST NOT be urlencoded.

    build_signature(\OAuthRequest $request, \OAuthConsumer $consumer, \OAuthToken $token) : string

the encoding is handled in OAuthRequest when the final request is serialized

### Parameters

#### $request

`\OAuthRequest`

#### $consumer

`\OAuthConsumer`

#### $token

`\OAuthToken`

### Returns

`string`

## Verifies that a given signature is correct

    check_signature(\OAuthRequest $request, \OAuthConsumer $consumer, \OAuthToken $token, string $signature) : bool

### Parameters

#### $request

`\OAuthRequest`

#### $consumer

`\OAuthConsumer`

#### $token

`\OAuthToken`

#### $signature

`string`

### Returns

`bool`

## Needs to return the name of the Signature Method (ie HMAC-SHA1)

    get_name() : string

### Returns

`string`