You declare the "shape" of the data as classes with attributes.

And each attribute has a type.

Then you create an instance of that class with some values and it will validate the values, convert them to the appropriate type (if that's the case) and give you an object with all the data.

And you get all the editor support with that resulting object.

An example from the official Pydantic docs:

          <name>type</name>
          <version>1.0.0+</version>
          <type>String</type>
          <required>true</required>
          <description>
            The Java type for this parameter. This is used to validate the result of any expressions used to calculate
            the value which should be injected into the Mojo for this parameter.
          </description>
        </field>
        <field>
          <name>required</name>

 */
class CacheControl internal constructor(
  /**
   * In a response, this field's name "no-cache" is misleading. It doesn't prevent us from caching
   * the response; it only means we have to validate the response with the origin server before
   * returning it. We can do this with a conditional GET.
   *
   * In a request, it means do not use a cache to satisfy the request.
   */

        assertThrows(SMBProtocolDecodingException.class, () -> resp.decode(packet, 0));
    }

    @Test
    void decodesSrvCopyChunkCopyResponse() throws Exception {
        // Validate createOutputDecodable() mapping and Decodable decode
        byte[] header = buildHeader(NtStatus.NT_STATUS_SUCCESS);

        // Prepare 3 ints: chunksWritten=1, chunkBytesWritten=2, totalBytesWritten=3

    @Test
    @DisplayName("Parse accepts non-zero outer tag numbers (current implementation behavior)")
    void testParseAcceptsNonZeroOuterTag() throws Exception {
        // Note: The current implementation does not validate the outer APPLICATION tag number
        // This test documents the actual behavior - any tag number is accepted
        byte[] token =

        // Directory leasing requires SMB 3.0 or higher
        // MS-SMB2: Level 2 leasing (which includes directory leasing) is only supported in SMB 3.0+
        // We'll validate this when we actually need to use the session

        // Request base lease
        Smb2LeaseKey leaseKey = baseLeaseManager.requestLease(directoryPath, requestedState);

        // Create directory cache entry

            assertFalse(UniAddress.isDotQuadIP(input));
        }

        @Test
        void shouldReturnTrueForInvalidOctetValues() {
            // isDotQuadIP does not validate octet values, only checks format
            assertTrue(UniAddress.isDotQuadIP("192.168.1.256"));
            assertTrue(UniAddress.isDotQuadIP("999.999.999.999"));
        }

        @Test

import org.junit.jupiter.api.Test;

/**
 * JUnit 5 tests for AndXServerMessageBlock in legacy smb1 package.
 *
 * The tests use small stub subclasses to drive encode/decode paths and
 * validate batching, chaining, signing, and NT_CREATE_ANDX extended handling.
 */
class AndXServerMessageBlockTest {

    /**
     * Test stub for AndXServerMessageBlock to control read/write logic.
     */

        // Then - all reads should return same result
        assertEquals(4, read1);
        assertEquals(4, read2);
        assertEquals(4, read3);
    }

    @Test
    @DisplayName("Should validate structure size before processing")
    void testStructureSizeValidation() {
        // Given various invalid structure sizes
        int[] invalidSizes = { -1, 0, 1, 2, 3, 5, 6, 8, 16, 32, 64, 128, 256, 512, 1024 };

            });
        }
    }

    @Nested
    @DisplayName("Encoding Tests")
    class EncodingTests {

        @Test
        @DisplayName("encode should validate size calculation")
        void testEncodeValidSize() {
            byte[] buffer = new byte[1024];
            testRequest.setTestSize(64);
            testRequest.setTestLength(64);