presto-spi/src/main/java/io/prestosql/spi/type/AbstractType.java/AbstractType/equals
class AbstractType:    @Override
    public boolean equals(Object o)
    {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }

        return this.getTypeSignature().equals(((Type) o).getTypeSignature());
    }