presto-example-http/src/main/java/io/prestosql/plugin/example/ExampleTable.java/ExampleTable/ExampleTable
class ExampleTable:    @JsonCreator
    public ExampleTable(
            @JsonProperty("name") String name,
            @JsonProperty("columns") List<ExampleColumn> columns,
            @JsonProperty("sources") List<URI> sources)
    {
        checkArgument(!isNullOrEmpty(name), "name is null or is empty");
        this.name = requireNonNull(name, "name is null");
        this.columns = ImmutableList.copyOf(requireNonNull(columns, "columns is null"));
        this.sources = ImmutableList.copyOf(requireNonNull(sources, "sources is null"));

        ImmutableList.Builder<ColumnMetadata> columnsMetadata = ImmutableList.builder();
        for (ExampleColumn column : this.columns) {
            columnsMetadata.add(new ColumnMetadata(column.getName(), column.getType()));
        }
        this.columnsMetadata = columnsMetadata.build();
    }