GoLand in the same package in a directory can not be called

Code structure:

 

package three codes are pipefilter, execution split_filter_test.go will prompt undefined: xxxxxxx

Golang actual method can make up their own wholly another document, reference is certainly not a problem, the main problem is to appear on the compilation

1, into the Test kind directory

2, directory directory can be changed to code, compile a directory form

Then run it