static Keyword from(String keyword) {
            switch (keyword) {
                case "true":
                    return Keyword.TRUE;
                case "false":
                    return Keyword.FALSE;
                case "null":
                    return Keyword.NULL;
                default:
                    return null;
            }
        }
Parse a Node identifier String, taking into account keywords and forward references.

@param loader     IDL parser.
@param identifier Identifier to parse.
@param location   Source location to assign to the identifier.
@return Returns the parsed identifier.
smithy-model/src/main/java/software/amazon/smithy/model/loader/IdlNodeParser.java