StepFile → StepData Relation

File in src/StepFile	Includes file in src/StepData
StepFile_Read.hxx	StepData_FileRecognizer.hxx
StepFile_Read.hxx	StepData_Protocol.hxx
StepFile_Read.hxx	StepData_StepModel.hxx
StepFile_Transfer.hxx	StepData_StepModel.hxx