src/Mapping/ClassMetadata.php
public function setAttributeList($attributeList): self
    {
        $this->attributeList = [];

        foreach ($attributeList as $attribute) {
            $this->attributeList[$attribute->getSerializedKey()] = $attribute;

            if ($attribute->isIdentifier()) {
                if ($this->identifierAttribute) {
                    throw new MoreThanOneIdentifierException(
                        sprintf(
                            'Class metadata for model "%s" already has an identifier named "%s". Only one identifier is allowed.',
                            $this->modelName,
                            $this->identifierAttribute->getSerializedKey()
                        )
                    );
                }

                $this->identifierAttribute = $attribute;
            }
        }

        return $this;
    }
public function setAttributeList($attributeList): self
    {
        $this->attributeList = [];

        foreach ($attributeList as $attribute) {
            $this->attributeList[$attribute->getSerializedKey()] = $attribute;

            if ($attribute->isIdentifier()) {
                if ($this->identifierAttribute) {
                    throw new MoreThanOneIdentifierException(
                        sprintf(
                            'Class metadata for model "%s" already has an identifier named "%s". Only one identifier is allowed.',
                            $this->modelName,
                            $this->identifierAttribute->getSerializedKey()
                        )
                    );
                }

                $this->identifierAttribute = $attribute;
            }
        }

        return $this;
    }
Setter for attributeList

@param  iterable<Attribute> $attributeList