/// check

So, with the same Python type declaration, **FastAPI** gives you data validation.

Notice that the error also clearly states exactly the point where the validation didn't pass.

This is incredibly helpful while developing and debugging code that interacts with your API.

///

## Documentation { #documentation }

   * {@code array}, or {@code -1} if there is no such occurrence.
   *
   * <p>More formally, returns the lowest index {@code i} such that {@code Arrays.copyOfRange(array,
   * i, i + target.length)} contains exactly the same elements as {@code target}.
   *
   * <p>Note that this always returns {@code -1} when {@code target} contains {@code NaN}.
   *
   * @param array the array to search for the sequence {@code target}

For that, we update the Pydantic model `TokenData` with a new property `scopes`.

By validating the data with Pydantic we can make sure that we have, for example, exactly a `list` of `str` with the scopes and a `str` with the `username`.

Instead of, for example, a `dict`, or something else, as it could break the application at some point later, making it a security risk.

		panic("Descriptors must be set")
	}

	// For bools A and B, A XOR B <=> A != B.
	isExactlyOneSet := (mg.loader == nil) != (mg.bucketLoader == nil)
	if !isExactlyOneSet {
		panic("Exactly one Loader function must be set")
	}

	mg.descriptorMap = make(map[MetricName]MetricDescriptor, len(mg.Descriptors))
	for _, desc := range mg.Descriptors {
		mg.descriptorMap[desc.Name] = desc
	}
}

      case CEILING:
        return Long.SIZE - Long.numberOfLeadingZeros(x - 1);

      case HALF_DOWN:
      case HALF_UP:
      case HALF_EVEN:
        // Since sqrt(2) is irrational, log2(x) - logFloor cannot be exactly 0.5
        int leadingZeros = Long.numberOfLeadingZeros(x);
        long cmp = MAX_POWER_OF_SQRT2_UNSIGNED >>> leadingZeros;
        // floor(2^(logFloor + 0.5))
        int logFloor = (Long.SIZE - 1) - leadingZeros;

   * Otherwise this returns an empty list of challenges.
   *
   * If a challenge uses the `token68` variant instead of auth params, there is exactly one
   * auth param in the challenge at key null. Invalid headers and challenges are ignored.
   * No semantic validation is done, for example that `Basic` auth must have a `realm`

        // Set structure size to 9
        SMBUtil.writeInt2(9, buffer, bufferIndex);
        // Set buffer offset
        SMBUtil.writeInt2(dataOffset, buffer, bufferIndex + 2);
        // Set buffer length exactly at boundary
        SMBUtil.writeInt4(432, buffer, bufferIndex + 4); // 512 - 80

        response = spy(response);
        when(response.getHeaderStart()).thenReturn(0);

   * {@code array}, or {@code -1} if there is no such occurrence.
   *
   * <p>More formally, returns the lowest index {@code i} such that {@code Arrays.copyOfRange(array,
   * i, i + target.length)} contains exactly the same elements as {@code target}.
   *
   * <p>Note that this always returns {@code -1} when {@code target} contains {@code NaN}.
   *
   * @param array the array to search for the sequence {@code target}

    }

    @Test
    @DisplayName("readPacketType with special stream returning -1 should return -1")
    void testReadPacketTypeSpecialStream() throws IOException {
        // Create a mock stream that returns exactly -1 on first read (special case)
        when(mockInputStream.read(any(byte[].class), anyInt(), anyInt())).thenReturn(-1); // Immediate EOF

        byte[] buffer = new byte[10];

Like in:

```
http://127.0.0.1:8000/items/?item-query=foobaritems
```

But `item-query` is not a valid Python variable name.

The closest would be `item_query`.

But you still need it to be exactly `item-query`...

Then you can declare an `alias`, and that alias is what will be used to find the parameter value:

{* ../../docs_src/query_params_str_validations/tutorial009_an_py310.py hl[9] *}