private function collectFunction(array $start, array $end, array $declaration, int $coverage = 0) : void
    {
        $this->fileCoverage['fnMap'][] = [
            'name' => '(anonymous_' . $this->funcCount . ')',
            'decl' => $declaration,
            'loc' => ['start' => $start, 'end' => $end],
        ];

        $this->fileCoverage['f'][] = $coverage;

        // Collect statements as well, one for entire function, one just for function declaration
        $this->collectStatement($start, $end, $coverage);
        $this->collectStatement($declaration['start'], $declaration['end'], $coverage);

        ++$this->funcCount;
    }