protected function determineContext(array &$data)
    {
        // Get the variable names defined in the AST
        $refs = 0;
        $vars = array_map(function ($node) use (&$refs) {
            if ($node->byRef) {
                $refs++;
            }
            if ($node->var instanceof VariableNode) {
                // For PHP-Parser >=4.0
                return $node->var->name;
            } else {
                // For PHP-Parser <4.0
                return $node->var;
            }
        }, $data['ast']->uses);
        $data['hasRefs'] = ($refs > 0);

        // Get the variable names and values using reflection
        $values = $data['reflection']->getStaticVariables();

        // Combine the names and values to create the canonical context.
        foreach ($vars as $name) {
            if (isset($values[$name])) {
                $data['context'][$name] = $values[$name];
            }
        }
    }
protected function determineContext(array &$data)
    {
        // Get the variable names defined in the AST
        $refs = 0;
        $vars = array_map(function ($node) use (&$refs) {
            if ($node->byRef) {
                $refs++;
            }
            if ($node->var instanceof VariableNode) {
                // For PHP-Parser >=4.0
                return $node->var->name;
            } else {
                // For PHP-Parser <4.0
                return $node->var;
            }
        }, $data['ast']->uses);
        $data['hasRefs'] = ($refs > 0);

        // Get the variable names and values using reflection
        $values = $data['reflection']->getStaticVariables();

        // Combine the names and values to create the canonical context.
        foreach ($vars as $name) {
            if (isset($values[$name])) {
                $data['context'][$name] = $values[$name];
            }
        }
    }
Returns the variables that in the "use" clause of the closure definition.
These are referred to as the "used variables", "static variables", or
"closed upon variables", "context" of the closure.

@param array $data