# Body - Multiple Parameters

Now that we have seen how to use `Path` and `Query`, let's see more advanced uses of request body declarations.

## Mix `Path`, `Query` and body parameters

First, of course, you can mix `Path`, `Query` and request body parameter declarations freely and **FastAPI** will know what to do.

And you can also declare body parameters as optional, by setting the default to `None`:

=== "Python 3.10+"

* Calling your dependency ("dependable") function with the correct parameters.
* Get the result from your function.
* Assign that result to the parameter in your *path operation function*.

```mermaid
graph TB

common_parameters(["common_parameters"])
read_items["/items/"]
read_users["/users/"]

common_parameters --> read_items
common_parameters --> read_users
```

  }

  public void testConstructor_parameters() throws Exception {
    Invokable<?, Prepender> delegate = Prepender.constructor(String.class, int.class);
    ImmutableList<Parameter> parameters = delegate.getParameters();
    assertEquals(2, parameters.size());
    assertEquals(String.class, parameters.get(0).getType().getType());
    assertTrue(parameters.get(0).isAnnotationPresent(NotBlank.class));

                all_parameters = {
                    (param["in"], param["name"]): param for param in parameters
                }
                required_parameters = {
                    (param["in"], param["name"]): param
                    for param in parameters
                    if param.get("required")
                }
                # Make sure required definitions of the same parameter take precedence

    }

    public void setParameters_Equal(String parameters) {
        setParameters_Term(parameters, null);
    }

    public void setParameters_Equal(String parameters, ConditionOptionCall<TermQueryBuilder> opLambda) {
        setParameters_Term(parameters, opLambda);
    }

    public void setParameters_Term(String parameters) {
        setParameters_Term(parameters, null);
    }

            Map<String, Object> parameters = new HashMap<>();
            // NOTE: These parameter names _must_ match the setter names in ReleaseNotesTransformer
            parameters.put("baseCss", getBaseCssFile().get().getAsFile());
            parameters.put("releaseNotesCss", getReleaseNotesCssFile().get().getAsFile());

  /** True if the agreed upon extension parameters includes "client_no_context_takeover". */
  @JvmField val clientNoContextTakeover: Boolean = false,
  /** Should be a value in [8..15]. Any value in that range is acceptable by OkHttp. */
  @JvmField val serverMaxWindowBits: Int? = null,
  /** True if the agreed upon extension parameters includes "server_no_context_takeover". */

        router_sig = inspect.signature(router_method)
        app_sig = inspect.signature(app_method)
        param: inspect.Parameter
        for key, param in base_sig.parameters.items():
            router_param: inspect.Parameter = router_sig.parameters[key]
            app_param: inspect.Parameter = app_sig.parameters[key]
            assert param.annotation == router_param.annotation
            assert param.annotation == app_param.annotation

   * parameters.
   */
  public MediaType withoutParameters() {
    return parameters.isEmpty() ? this : create(type, subtype);
  }

  /**
   * Replaces all parameters with the given parameters.
   *
   * @throws IllegalArgumentException if any parameter or value is invalid
   */

        this.hostname = value;
    }

    public String getParameters() {
        checkSpecifiedProperty("parameters");
        return convertEmptyToNull(parameters);
    }

    public void setParameters(String value) {
        registerModifiedProperty("parameters");
        this.parameters = value;
    }

    public String getPassword() {
        checkSpecifiedProperty("password");