Improve 'extend' statement

smnp/token/tokenizer.py

@@ -51,6 +51,7 @@ tokenizers = (
     separated(defaultTokenizer(TokenType.EXTEND)),
     separated(defaultTokenizer(TokenType.IMPORT)),
     separated(defaultTokenizer(TokenType.FROM)),
+    separated(defaultTokenizer(TokenType.WITH)),
     separated(defaultTokenizer(TokenType.ELSE)),
     separated(defaultTokenizer(TokenType.AND)),
     separated(defaultTokenizer(TokenType.NOT)),

smnp/token/type.py

@@ -36,6 +36,7 @@ class TokenType(Enum):
     EXTEND = 'extend'
     IMPORT = 'import'
     FROM = 'from'
+    WITH = 'with'
     ELSE = 'else'
     IF = 'if'
     AS = 'as'