private static boolean isValidEncoding(String encoding) {
        return RequestCompressionTrait.SUPPORTED_COMPRESSION_ALGORITHMS.contains(encoding.toLowerCase());
    }
Validates the requestCompression trait.

- Validates that the operation input has no member with both streaming and
  requiresLength traits applied
- Validate encodings has at least one compression algorithm
- Validate encodings are all supported compression algorithms
smithy-model/src/main/java/software/amazon/smithy/model/validation/validators/RequestCompressionTraitValidator.java