src/Model/Context.php
public function add($name, $value)
    {
        if (array_key_exists($name, $this->storage)) {
            throw new AlreadyDefinedException(sprintf('Context value with key `%s` already defined', $name));
        }

        $this->storage[$name] = $value;
    }
public function add($name, $value)
    {
        if (array_key_exists($name, $this->storage)) {
            throw new AlreadyDefinedException(sprintf('Context value with key `%s` already defined', $name));
        }

        $this->storage[$name] = $value;
    }
Add a context value. The key must be unique and cannot be replaced

@param string $name
@param mixed $value

@return void
@throws AlreadyDefinedException