Add example of passing a class as the function

examples/call_async_class.py

@@ -0,0 +1,23 @@
+"""
+Simple Lithops example using one single function invocation
+with a class as a function and a function as a parameter
+"""
+import lithops
+
+def mult(x, y):
+    return x + y
+
+
+class MyClass:
+    def __init__(self, base) -> None:
+        self.base = base
+
+    def __call__(self, x, fn) -> int:
+        return fn(self.base, x)
+
+
+if __name__ == '__main__':
+    fexec = lithops.FunctionExecutor()
+    inst = MyClass(7)
+    fexec.map(inst, [(8, mult), (6, mult)])
+    print(fexec.get_result())