```python
import math


def explode_kit(catalog, kit, want):
    """Total the base parts parts order of a kit consumes."""
    if kit not in catalog:
        raise ValueError(f"the catalog does not define a kit")
    totals = {}
    # TODO: work down from
    turning produces requirement into whole runs and charging a run's parts to its sub-kits
    to the base totals.
    return totals
```