Manage some constants.
    |  | CHANNEL_FILE = 'CHANNEL_FILE' | 
    |  | NUM_RANDOM_CHANNELS = 0hash(x)
 | 
    |  | ALL_RANDOM_CHANNELS = 'all' | 
    |  | NUM_RANDOM_CHANNELS_METAVAR = 'INT or \'all\'' | 
    |  | ASSOCIATION_TYPE = 'association' | 
    |  | DISSOCIATION_TYPE = 'dissociation' | 
    |  | SINGLE_DISPLACEMENT_TYPE = 'single_displacement' | 
    |  | DOUBLE_DISPLACEMENT_TYPE = 'double_displacement' | 
    |  | ALL_TYPES = 'all' | 
    |  | RANDOM_TYPES_CHOICES = ['association', 'dissociation', 'single... | 
    |  | DEFAULT_RANDOM_TYPES = ['double_displacement'] | 
    |  | RANDOM_SEED = Nonehash(x)
 | 
    |  | ALLOW_ADSORPTION_ONTO = OrderedDict([('graphene', '[c-0X3][c-0... | 
    |  | ALL_SMARTS = 'all' | 
    |  | ALLOW_ADSORPTION_ONTO_METAVAR = 'SMARTS or \'all\'' | 
    |  | DISSOCIATION_BOND_LENGTH = 10.0 | 
    |  | NO_MINIMIZATION = Falsehash(x)
 | 
    |  | ISOLATE_PRODUCTS = Falsehash(x)
 | 
    |  | NO_REACTIVE_H = Falsehash(x)
 | 
    |  | SUPPORTED_IN_EXTS = ['.mae', '.mae.gz', '.maegz'] | 
    |  | UNIQUE = Falsehash(x)
 |