======== #1 ========

__name__, __source__, __symbol__, adder, foo

======== #2 ========

ImportError: module symbol conflicts with an existing variable 're'
no error

======== #3 ========

string in m1
string m1.m2
string m1.m2.m3
string m1.m2.m3.m4
string m1.m2.m3.m4.m5

======== #4 symbol confliction in hierarchical module ========

[sub1]
import(subsub.test)
[sub2]
import(subsub.test)

Check if symbol confliction is mistakenly detected for 'test' in subsub module. 
OK
