`Something went wrong in initial mypy run.` on `langchain` project

[tyuldashev]

Description

UTBot cannot generate test on specific project, it fails with Something went wrong in initial mypy run error

To Reproduce

Steps to reproduce the behavior:

For some reason it's reproducible for me only in original project, when I copy the class code and import other langchain modules then no exception happen (though it still cannot generate due timeout).

1. Clone the project - https://github.com/hwchase17/langchain
2. Invoke test generation for langchain.indexes.graph.GraphIndexCreator class

Expected behavior

Tests are supposed to be generated.

Actual behavior

No tests are generated, exception is thrown.

Visual proofs (screenshots, logs, images)

java.lang.IllegalStateException: Something went wrong in initial mypy run. 
Python stderr 
Mypy stderr: 
	at org.utbot.python.newtyping.mypy.RunMypyKt.readMypyAnnotationStorageAndInitialErrors(RunMypy.kt:50)
	at org.utbot.python.PythonTestGenerationProcessor.processTestGeneration(PythonTestGenerationProcessor.kt:82)
	at org.utbot.python.PythonTestGenerationProcessor.processTestGeneration$default(PythonTestGenerationProcessor.kt:32)
	at org.utbot.intellij.plugin.language.python.PythonDialogProcessor$createTests$1.run(PythonDialogProcessor.kt:171)
	at com.intellij.openapi.progress.impl.CoreProgressManager.startTask(CoreProgressManager.java:442)
	at com.intellij.openapi.progress.impl.ProgressManagerImpl.startTask(ProgressManagerImpl.java:114)
	at com.intellij.openapi.progress.impl.CoreProgressManager.lambda$runProcessWithProgressAsynchronously$5(CoreProgressManager.java:493)
	at com.intellij.openapi.progress.impl.ProgressRunner.lambda$submit$3(ProgressRunner.java:252)
	at com.intellij.openapi.progress.impl.CoreProgressManager.lambda$runProcess$2(CoreProgressManager.java:188)
	at com.intellij.openapi.progress.impl.CoreProgressManager.lambda$executeProcessUnderProgress$12(CoreProgressManager.java:608)
	at com.intellij.openapi.progress.impl.CoreProgressManager.registerIndicatorAndRun(CoreProgressManager.java:683)
	at com.intellij.openapi.progress.impl.CoreProgressManager.computeUnderProgress(CoreProgressManager.java:639)
	at com.intellij.openapi.progress.impl.CoreProgressManager.executeProcessUnderProgress(CoreProgressManager.java:607)
	at com.intellij.openapi.progress.impl.ProgressManagerImpl.executeProcessUnderProgress(ProgressManagerImpl.java:60)
	at com.intellij.openapi.progress.impl.CoreProgressManager.runProcess(CoreProgressManager.java:175)
	at com.intellij.openapi.progress.impl.ProgressRunner.lambda$submit$4(ProgressRunner.java:252)
	at java.base/java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1768)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
	at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1$1.run(Executors.java:702)
	at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1$1.run(Executors.java:699)
	at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
	at java.base/java.util.concurrent.Executors$PrivilegedThreadFactory$1.run(Executors.java:699)
	at java.base/java.lang.Thread.run(Thread.java:833)

[tamarinvs19]

Problem from this issue has been fixed in #1890 but we still can't generate useful tests for this class because it contains "fake"
immutable fields

[tyuldashev]

No such exception any more.