Phan\AST\UnionTypeVisitor::visitVar PHP Method

    public function visitVar(Node $node) : UnionType
    {
        // $$var or ${...} (whose idea was that anyway?)
        if ($node->children['name'] instanceof Node && ($node->children['name']->kind == \ast\AST_VAR || $node->children['name']->kind == \ast\AST_BINARY_OP)) {
            return MixedType::instance()->asUnionType();
        }
        // This is nonsense. Give up.
        if ($node->children['name'] instanceof Node) {
            return new UnionType();
        }
        $variable_name = $node->children['name'];
        if (!$this->context->getScope()->hasVariableWithName($variable_name)) {
            if (Variable::isSuperglobalVariableWithName($variable_name)) {
                return Variable::getUnionTypeOfHardcodedGlobalVariableWithName($variable_name, $this->context);
            }
            if (!Config::get()->ignore_undeclared_variables_in_global_scope || !$this->context->isInGlobalScope()) {
                throw new IssueException(Issue::fromType(Issue::UndeclaredVariable)($this->context->getFile(), $node->lineno ?? 0, [$variable_name]));
            }
        } else {
            $variable = $this->context->getScope()->getVariableByName($variable_name);
            return $variable->getUnionType();
        }
        return new UnionType();
    }