assertNull(converter.convert(null));
    assertNull(converter.reverse().convert(null));

    assertEquals((Integer) 5, converter.convert("5"));
    assertEquals("5", converter.reverse().convert(5));
  }

  // Null-passthrough violates our nullness annotations, so we don't support it under J2KT.
  @J2ktIncompatible

                            }))
                    .installationToolchainsSource(convert(request.getGlobalToolchainsSource()))
                    .userToolchainsSource(convert(request.getUserToolchainsSource()))
                    .build());

            return new DefaultToolchainsBuildingResult(
                    new PersistedToolchains(result.getEffectiveToolchains()), convert(result.getProblems()));
        } catch (ToolchainsBuilderException e) {

  public void testStringConverter_convert() {
    Converter<String, TestEnum> converter = Enums.stringConverter(TestEnum.class);
    assertEquals(TestEnum.CHEETO, converter.convert("CHEETO"));
    assertEquals(TestEnum.HONDA, converter.convert("HONDA"));
    assertEquals(TestEnum.POODLE, converter.convert("POODLE"));
    assertNull(converter.convert(null));
    assertNull(converter.reverse().convert(null));
  }

# JSON Compatible Encoder

There are some cases where you might need to convert a data type (like a Pydantic model) to something compatible with JSON (like a `dict`, `list`, etc).

For example, if you need to store it in a database.

For that, **FastAPI** provides a `jsonable_encoder()` function.

## Using the `jsonable_encoder`

Let's imagine that you have a database `fake_db` that only receives JSON compatible data.

    }

    /**
     * Parses a sequence of XML elements and converts them to the appropriate array type.
     *
     * @param parser The XML parser
     * @return Converted array instance
     */
    private Object parseArray(final MXParser parser, final TypeLiteral<?> toType) throws Exception {
        // convert to a collection first then convert that into an array

  public void testStringConverter_convert() {
    Converter<String, Double> converter = Doubles.stringConverter();
    assertThat(converter.convert("1.0")).isEqualTo((Double) 1.0);
    assertThat(converter.convert("0.0")).isEqualTo((Double) 0.0);
    assertThat(converter.convert("-1.0")).isEqualTo((Double) (-1.0));
    assertThat(converter.convert("1")).isEqualTo((Double) 1.0);
    assertThat(converter.convert("0")).isEqualTo((Double) 0.0);

    if (MINUTES.convert(nanos, NANOSECONDS) > 0) {
      return MINUTES;
    }
    if (SECONDS.convert(nanos, NANOSECONDS) > 0) {
      return SECONDS;
    }
    if (MILLISECONDS.convert(nanos, NANOSECONDS) > 0) {
      return MILLISECONDS;
    }
    if (MICROSECONDS.convert(nanos, NANOSECONDS) > 0) {
      return MICROSECONDS;
    }
    return NANOSECONDS;
  }

  private static String abbreviate(TimeUnit unit) {

            result.addDependency(convert(dependency, stereotypes));
        }

        DependencyManagement mgmt = model.getDependencyManagement();
        if (mgmt != null) {
            for (org.apache.maven.model.Dependency dependency : mgmt.getDependencies()) {
                result.addManagedDependency(convert(dependency, stereotypes));
            }
        }

  public void testStringConverter_convert() {
    Converter<String, Integer> converter = Ints.stringConverter();
    assertThat(converter.convert("1")).isEqualTo((Integer) 1);
    assertThat(converter.convert("0")).isEqualTo((Integer) 0);
    assertThat(converter.convert("-1")).isEqualTo((Integer) (-1));
    assertThat(converter.convert("0xff")).isEqualTo((Integer) 255);
    assertThat(converter.convert("0xFF")).isEqualTo((Integer) 255);

  public void testStringConverter_convert() {
    Converter<String, Long> converter = Longs.stringConverter();
    assertThat(converter.convert("1")).isEqualTo((Long) 1L);
    assertThat(converter.convert("0")).isEqualTo((Long) 0L);
    assertThat(converter.convert("-1")).isEqualTo((Long) (-1L));
    assertThat(converter.convert("0xff")).isEqualTo((Long) 255L);
    assertThat(converter.convert("0xFF")).isEqualTo((Long) 255L);