static BigDecimal parseNumber(String token) {
        try {
            return new BigDecimal(token);
        } catch (NumberFormatException e) {
            return null;
        }
    }
Compares the given attribute values by flattening each side of the
comparison, and comparing each value.

<p>This method is necessary in order to support matching on projections
using projection semantics.

@param singleComparison Comparison to apply to each element.
@return Returns the created comparator.
smithy-model/src/main/java/software/amazon/smithy/model/selector/AttributeComparator.java