can't find constructor references of indirectly import

[zxt5105515]

i need to find all methods usage in a library testLib , so i search all modules and classes in testLib/index.d.ts ,then search all methods usage, everything works fine but the constructor usage can't be find .
i use a common.ts to wrap testLib's class , if i import class directly from testLib, constructor references works fine .
please help.

my testProject
--Typing
----testLib
------index.d.ts
--index.ts
--common.ts

index.d.ts

declare namespace Name1 {
  declare namespace Name2{
    class MyClassA{
       public fun1():void
       public constructor()        //can't find references 
    }
  }
}

common.ts

import MyClassA  = Name1.Name2.MyClassA
export {MyClassA}

index.ts

import { MyClassA} from "./common"
let a = new MyClassA()
a.fun1()

my morph project is simple ,

//setup project
//...
//get sourcefile from 'Typing/testLib/index.d.ts'
let sourceFile:SourceFile = ... 
//get MyClass class in sourceFile
let class:ClassDeclaration =  ...

//search refs
for (let fun of class.getMethods()) {
    let refs = fun.findReferences() // refs length is 1 ,and it's right ,ref by index.ts      
}

for (let fun of class.getConstructors()) {
    let refs = fun.findReferences()   //refs length is 0 ,can't find  constructor usage
}