def main():
my_binary_tree = BinaryTree('A')
print(my_binary_tree)
print(repr(my_binary_tree))
my_binary_tree.add_val_l('B')
print(my_binary_tree)
print(repr(my_binary_tree))
my_binary_tree.add_val_l('C')
print(my_binary_tree)
print(repr(my_binary_tree))
my_binary_tree.add_val_l('D')
print(my_binary_tree)
print(repr(my_binary_tree))
my_binary_tree.add_val_r('E')
print(my_binary_tree)
print(repr(my_binary_tree))
my_binary_tree.add_val_r('F')
print(my_binary_tree)
print(repr(my_binary_tree))
if my_binary_tree.contains('E'):
# This should be the case:
print("This tree contains 'E'")
else:
print("This tree does not contain 'E'")
if my_binary_tree.contains('J'):
print("This tree contains 'J'")
else:
# This should be the case:
print("This tree does not contain 'J'")
