duplicate symbol _OBJC_CLASS_$_PSAnswersBlock in:
    /Users/Nikolay/Library/Developer/Xcode/DerivedData/perfectStore-hjtfoqhvajeyigbcaenuvmqjgzew/Build/Intermediates/perfectStore.build/Debug-iphonesimulator/perfectStore.build/Objects-normal/x86_64/PSAnswersBlock+CoreDataClass.o
duplicate symbol _OBJC_METACLASS_$_PSAnswersBlock in:
    /Users/Nikolay/Library/Developer/Xcode/DerivedData/perfectStore-hjtfoqhvajeyigbcaenuvmqjgzew/Build/Intermediates/perfectStore.build/Debug-iphonesimulator/perfectStore.build/Objects-normal/x86_64/PSAnswersBlock+CoreDataClass.o
ld: 2 duplicate symbols for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)