Initial use of "yosmanyga/resource" library
Fixed typo
Added self validator
Added "ObjectReference" concept
Removed unused property and methods
Added alternative values for properties in constructors, added inheritance from general classes
Fixed docblock
Changed method to private
Added condition for empty value
Removed unused namespaces
Removed unused variable
Refactored normalizers to use common parent.
Changed variable name for item inside map function
Fixed typo
Added "yosmanyga/resource" vendor to composer
Changed normalizer
Fixed compiler type hint
Changed cache