code: public function get(string $name, string $default = ''): string
      {
          $val = \trim($this->data[$name] ?? '');
          
          if ($val !== '') {
              return $val;
          }
          
          $val = \getenv($name);
          
          if (!\is_string($val)) {
              return $default;
          }
          
          return ('' === ($val = \trim($val))) ? $default : $val;
      }
docs: Get the (string) value of an environment variable.
  
  @param string $name Name of the environment variable.
  @param string $default Default value to be used if no string value is set in env.
  @return string Value of the requested env var.