public void populateOriginalStructure(Structure dt) {
		structDT = dt;
		DataTypeComponent[] components = structDT.getDefinedComponents();
		for (DataTypeComponent component : components) {
			offsetToDataTypeMap.put((long) component.getOffset(), component.getDataType());
		}
		sizeOfStruct = structDT.getLength();
	}
Populate this builder with fields from a preexisting Structure.
The builder presumes it is rebuilding this Structure so it can check for
pathological containment issues.
@param dt is the preexisting Structure
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/data/NoisyStructureBuilder.java