presto-example-http/src/main/java/io/prestosql/plugin/example/ExampleColumnHandle.java/ExampleColumnHandle/equals
class ExampleColumnHandle:    @Override
    public boolean equals(Object obj)
    {
        if (this == obj) {
            return true;
        }
        if ((obj == null) || (getClass() != obj.getClass())) {
            return false;
        }

        ExampleColumnHandle other = (ExampleColumnHandle) obj;
        return columnName.equals(other.columnName);
    }