src/Reflection/ReflectionMethod.php
public function isConstructor() : bool
    {
        if (strtolower($this->getName()) === '__construct') {
            return true;
        }

        $declaringClass = $this->getDeclaringClass();
        if ($declaringClass->inNamespace()) {
            return false;
        }

        return strtolower($this->getName()) === strtolower($declaringClass->getShortName());
    }
public function isConstructor() : bool
    {
        if (strtolower($this->getName()) === '__construct') {
            return true;
        }

        $declaringClass = $this->getDeclaringClass();
        if ($declaringClass->inNamespace()) {
            return false;
        }

        return strtolower($this->getName()) === strtolower($declaringClass->getShortName());
    }
Is the method a constructor.