query_map = {
        'formula': [('CAS', QueryEngine.CASDetails), ('CID', QueryEngine.PUGRESTCID)],
        'image': [('CAS', QueryEngine.CASDetails)],
        'synonyms': [('CAS', QueryEngine.CASDetails)],
        'name_pretty': [('CAS', QueryEngine.CASDetails)],
        'SMILES': [('CAS', QueryEngine.CASDetails)],
        'InChI': [('CAS', QueryEngine.CASDetails)],
        'ExpProps': [('CAS', QueryEngine.CASDetails)],
        'MW': [('CAS', QueryEngine.CASDetails), ('CID', QueryEngine.PUGRESTprop)],
        'CAS': [(None, QueryEngine.CASDetails), ('CID', QueryEngine.PUGViewID)],
        'EC': [('CID', QueryEngine.PUGViewID)],
        'CID': [(None, QueryEngine.PUGRESTCID)],
        'GHS_class': [('CID', QueryEngine.PUGViewGHSClass)],
        'GHS_symbols': [('CID', QueryEngine.PUGViewGHS)],
        'signal': [('CID', QueryEngine.PUGViewGHS)],
        'hazards': [('CID', QueryEngine.PUGViewGHS)],
        'precautions': [('CID', QueryEngine.PUGViewGHS)],
    }