Fix review comments

Author: sergeypospelov

utbot-framework/src/main/kotlin/org/utbot/engine/Extensions.kt

@@ -111,6 +111,7 @@ fun SootMethod.canRetrieveBody() =
  */
 fun SootMethod.jimpleBody(): JimpleBody {
     declaringClass.adjustLevel(BODIES)
+    require(canRetrieveBody()) { "Can't retrieve body for $this"}
     return retrieveActiveBody() as JimpleBody
 }
 

utbot-framework/src/main/kotlin/org/utbot/engine/TraversalContext.kt

@@ -2,7 +2,7 @@ package org.utbot.engine
 
 /**
  * Represents a mutable _Context_ during the [ExecutionState] traversing. This _Context_ consists of all mutable and
- * immutable properties and fields which are created and updated during analysis of **one** Jimple instruction.
+ * immutable properties and fields which are created and updated during analysis of a **single** Jimple instruction.
  *
  * Traverser functions should be implemented as an extension functions with [TraversalContext] as a receiver.
  *
@@ -23,7 +23,7 @@ class TraversalContext {
     }
 
     /**
-     * New states from traversal.
+     * New states obtained from the traversal.
      */
     val nextStates: Collection<ExecutionState>
         get() = states

utbot-framework/src/main/kotlin/org/utbot/engine/Traverser.kt

@@ -6,7 +6,6 @@ import kotlinx.collections.immutable.persistentSetOf
 import kotlinx.collections.immutable.toPersistentList
 import kotlinx.collections.immutable.toPersistentMap
 import kotlinx.collections.immutable.toPersistentSet
-import kotlinx.coroutines.CancellationException
 import org.utbot.common.WorkaroundReason.HACK
 import org.utbot.common.WorkaroundReason.REMOVE_ANONYMOUS_CLASSES
 import org.utbot.common.findField
@@ -210,7 +209,7 @@ class Traverser(
     private val classLoader: ClassLoader
         get() = utContext.classLoader
 
-    // TODO: get rid of it
+    // TODO: move this and other mutable fields to [TraversalContext]
     lateinit var environment: Environment
     private val solver: UtSolver
         get() = environment.state.solver
@@ -279,13 +278,9 @@ class Traverser(
         } catch (ex: Throwable) {
             environment.state.close()
 
-            if (ex !is CancellationException) {
-                logger.error(ex) { "Test generation failed on stmt $currentStmt, symbolic stack trace:\n$symbolicStackTrace" }
-                // TODO: enrich with nice description for known issues
-                throw ex
-            } else {
-                logger.debug(ex) { "Cancellation happened" }
-            }
+            logger.error(ex) { "Test generation failed on stmt $currentStmt, symbolic stack trace:\n$symbolicStackTrace" }
+            // TODO: enrich with nice description for known issues
+            throw ex
         }
         queuedSymbolicStateUpdates = SymbolicStateUpdate()
         return context.nextStates
@@ -3294,7 +3289,8 @@ class Traverser(
             return
         }
 
-        //toplevel method
+        // toplevel method
+        // TODO: investigate very strange behavior when some constraints are not added leading to failing CodegenExampleTest::firstExampleTest fails
         val terminalExecutionState = environment.state.copy(
             symbolicState = symbolicState,
             methodResult = methodResult, // the way to put SymbolicResult into terminal state

utbot-framework/src/main/kotlin/org/utbot/engine/UtBotSymbolicEngine.kt

@@ -348,6 +348,8 @@ class UtBotSymbolicEngine(
                         // So we need to make it throw CancelledException by method below:
                         currentCoroutineContext().job.ensureActive()
                     }
+
+                    // TODO: think about concise modifying globalGraph in Traverser and UtBotSymbolicEngine
                     globalGraph.visitNode(state)
                 }
             }