src/Container.php
public function addEntry(string $id, EntryInterface $type): void
    {
        if (isset($this[$id])) {
            throw new ContainerException("Entry for identifier '$id' already exists");
        }

        $this->entryCache[$id] = $type;
    }
public function addEntry(string $id, EntryInterface $type): void
    {
        if (isset($this[$id])) {
            throw new ContainerException("Entry for identifier '$id' already exists");
        }

        $this->entryCache[$id] = $type;
    }
Adds an entry to the container.
@param string $id The identifier for the container entry
@param EntryInterface $type The container entry to add
@throws ContainerException If trying to add an entry to an identifier that already exists