uasyncio.core: Remove call_at() which takes absolute second time.

uasyncio uses different timebase than CPython's asyncio, so absolute
time scheduling compatible with it is impossible. Instead, there's
call_at_() which schedules using modular millisecond time.

Author: pfalcon

uasyncio.core/uasyncio/core.py

@@ -29,19 +29,14 @@ def create_task(self, coro):
         # CPython asyncio incompatibility: we don't return Task object
 
     def call_soon(self, callback, *args):
-        self.call_at(self.time(), callback, *args)
+        self.call_at_(self.time(), callback, *args)
 
     def call_later(self, delay, callback, *args):
-        self.call_at(time.ticks_add(self.time(), int(delay * 1000)), callback, *args)
+        self.call_at_(time.ticks_add(self.time(), int(delay * 1000)), callback, *args)
 
     def call_later_ms(self, delay, callback, args=()):
         self.call_at_(time.ticks_add(self.time(), delay), callback, args)
 
-    def call_at(self, time, callback, *args):
-        if __debug__ and DEBUG:
-            log.debug("Scheduling %s", (time, callback, args))
-        self.q.push(time, callback, args)
-
     def call_at_(self, time, callback, args=()):
         if __debug__ and DEBUG:
             log.debug("Scheduling %s", (time, callback, args))