verify(mockNdrBuffer).advance(8); // sub_authority advance (4 * 2)
            verify(mockNdrBuffer, times(2)).derive(anyInt());

            // Verify identifier_authority bytes (5 zeros + 1 five)
            verify(mockNdrBuffer, times(5)).enc_ndr_small((byte) 0);
            verify(mockNdrBuffer).enc_ndr_small((byte) 5);

            // Verify sub_authority values

                artifacts, rootArtifact, managedVersions, collectionRequest, source, collectionFilter, listeners, null);

        // We have metadata retrieval problems, or there are cycles that have been detected
        // so we give this back to the calling code and let them deal with this information
        // appropriately.

        if (result.hasMetadataResolutionExceptions()
                || result.hasVersionRangeViolations()

# Primeros Pasos { #first-steps }

El archivo FastAPI más simple podría verse así:

{* ../../docs_src/first_steps/tutorial001_py39.py *}

Copia eso en un archivo `main.py`.

Ejecuta el servidor en vivo:

<div class="termy">

```console
$ <font color="#4E9A06">fastapi</font> dev <u style="text-decoration-style:solid">main.py</u>

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