Added behavior subject

src/cpl_reactive_extensions/subject.py

@@ -7,14 +7,3 @@ class Subject(Observable):
         Observable.__init__(self)
 
         self._t = _t
-        self._value: T = None
-
-    @property
-    def value(self) -> T:
-        return self._value
-
-    def next(self, value: T):
-        if not isinstance(value, self._t):
-            raise TypeError(f"Expected {self._t.__name__} not {type(value).__name__}")
-
-        self._value = value