Error MissingPropertyException because of inconsistent scoping of local variables through this groovy kernel

[vrocky]

I am trying to run this code on groovy kernel and its give a strange error.

import java.util.zip.ZipEntry
import java.util.zip.ZipFile
zipInputFile = new ZipFile(file)
list = entires.toList();
zipInputFile.getInputStream(list.get(0))

This is the exception it is giving. while running the same code works with normal execution of groovy script.

groovy.lang.MissingPropertyException: No such property: file for class: script1622875172283
	at this cell line 3
	at com.twosigma.beakerx.groovy.evaluator.GroovyCodeRunner.runScript(GroovyCodeRunner.java:94)
	at com.twosigma.beakerx.groovy.evaluator.GroovyCodeRunner.call(GroovyCodeRunner.java:59)
	at com.twosigma.beakerx.groovy.evaluator.GroovyCodeRunner.call(GroovyCodeRunner.java:32)

Later I found this is happening because this kernel don't share local variables across the cells. But it still share local variable declared at last line.
So if I write,

import java.util.zip.ZipEntry
import java.util.zip.ZipFile

String file = "C:\\Users\\user\\.gradle\\caches\\modules-2\\files-2.1\\org.apache.bcel\\bcel\\6.5.0\\79b1975ec0c7a6c1a15e19fb3a58cc4041b4aaea\\bcel-6.5.0.jar"
zipInputFile = new ZipFile(file);

in a separate cell 'zipInputFile' will be scoped to next cell.

But when I declare variable mentioning its type. (both ways are valid in groovy)

import java.util.zip.ZipEntry
import java.util.zip.ZipFile

String file = "C:\\Users\\user\\.gradle\\caches\\modules-2\\files-2.1\\org.apache.bcel\\bcel\\6.5.0\\79b1975ec0c7a6c1a15e19fb3a58cc4041b4aaea\\bcel-6.5.0.jar"
ZipFile zipInputFile = new ZipFile(file);

The zipInputFile will not get scoped to the next cell. Why is this inconsistency ?