presto-main/src/main/java/io/prestosql/metadata/PolymorphicScalarFunctionBuilder.java/SpecializeContext/SpecializeContext
class SpecializeContext:        SpecializeContext(BoundVariables boundVariables, List<Type> parameterTypes, Type returnType)
        {
            this.boundVariables = requireNonNull(boundVariables, "boundVariables is null");
            this.parameterTypes = requireNonNull(parameterTypes, "parameterTypes is null");
            this.returnType = requireNonNull(returnType, "returnType is null");
        }