How does OpenClover count complexity for method?

[Alexey Ulasevich]

I have a method in a class:

    public boolean tryFile() throws IOException {

        File file = File.createTempFile("test", "dat");
           file.deleteOnExit();
        try (FileOutputStream fos = new FileOutputStream(file)) {
            fos.write(20);
        }

        return file.exists();
    }

According OpenClover documentation:

Method Complexity

Cyclomatic complexity of a single method. It's calculated as follows:

empty method complexity == 1
simple statement complexity == 0
switch block complexity == number of case statements
try catch block complexity == number of catch statements
ternary expression complexity == 1
boolean expression complexity == number of && or || in expression

In report generated by OpenClover (version 4.4.1) the complexity for this method equals 3. Why? How it was counted?

PS. For example in JaCoCo report I see Ctx=1 for this method.

[Marek Parfianowicz]

From https://github.com/openclover/clover/blob/master/clover-core/src/main/java/com/atlassian/clover/instr/java/java.g

tryCatchBlock [boolean labelled] returns [CloverToken last]
{
  last = null;
  int complexity = 0;
  ContextSet saveContext = getCurrentContext();
}
    :   tr:"try" (lp:LPAREN {insertAutoCloseableClassDecl((CloverToken)tr);} declaration {complexity++; instrArmDecl(((CloverToken)lp).getNext(), (CloverToken)LT(0), saveContext);} (semi:SEMI declaration {complexity++; instrArmDecl(((CloverToken)semi).getNext(), (CloverToken)LT(0), saveContext);})* (SEMI)? rp:RPAREN )?
        {enterContext(ContextStore.CONTEXT_TRY); saveContext = getCurrentContext();}
            last=compoundStatement
        {exitContext();}
        (last=handler {complexity++;})*
        ( "finally"
            {enterContext(ContextStore.CONTEXT_FINALLY); saveContext = getCurrentContext();}
            last=compoundStatement
            {exitContext();}
        )?
        { if (!labelled) {
                instrInlineBefore((CloverToken)tr, last, saveContext, complexity);
            }
        }
    ;

* 1st comes from the try-with-resources block:

try (FileOutputStream fos = new FileOutputStream(file))

* 2nd comes from the method entry as per docs

I'm not sure about the 3rd one...