public FieldConfig::isReadOnly()

Field-type specific settings. An array of key/value pairs, The keys and default values are defined by the field type.

protected FieldStorageConfig::getFieldItemClass()

public FieldStorageConfig::__construct(array $values

public FieldStorageConfig::getPropertyNames()

The field name. This is the name of the property under which the field values are placed in an entity: $entity->{$field_name}. The maximum