# Development - Contributing

First, you might want to see the basic ways to [help FastAPI and get help](help-fastapi.md){.internal-link target=_blank}.

## Developing

If you already cloned the <a href="https://github.com/fastapi/fastapi" class="external-link" target="_blank">fastapi repository</a> and you want to deep dive in the code, here are some guidelines to set up your environment.

### Virtual environment

     * @throws CIFSUnsupportedCryptoException if Provider has already been initialized.
     */
    public static void initProvider(final Provider customProvider) throws CIFSUnsupportedCryptoException {
        if (provider != null) {
            throw new CIFSUnsupportedCryptoException(
                    "Provider can't be re-initialized. Provider has already been initialized with " + provider.getInfo());
        }

R8 / ProGuard
=============

If you use OkHttp as a dependency in an Android project which uses R8 as a default compiler you
don't have to do anything. The specific rules are [already bundled][okhttp3_pro] into the JAR which can be
interpreted by R8 automatically.

If you, however, don't use R8 you have to apply the rules from [this file][okhttp3_pro]. You might
also need rules from [Okio][okio] which is a dependency of this library.

  private HostSpecifier(String canonicalForm) {
    this.canonicalForm = canonicalForm;
  }

  /**
   * Returns a {@code HostSpecifier} built from the provided {@code specifier}, which is already
   * known to be valid. If the {@code specifier} might be invalid, use {@link #from(String)}
   * instead.
   *
   * <p>The specifier must be in one of these formats:
   *
   * <ul>

    }

    /**
     * Stores an access result in the data store.
     *
     * @param accessResult the access result to store
     * @throws CrawlerSystemException if the access result is null or already exists
     */
    @Override
    public void store(final AccessResultImpl<Long> accessResult) {
        if (accessResult == null) {
            throw new CrawlerSystemException("AccessResult is null.");
        }

    if (force) {
      if (valueEntry != ABSENT) {
        removeEntryValueHashKnown(valueEntry, valueHash);
      }
    } else {
      checkArgument(valueEntry == ABSENT, "Value already present: %s", value);
    }

    ensureCapacity(size + 1);
    keys[size] = key;
    values[size] = value;

    insertIntoTableKToV(size, keyHash);
    insertIntoTableVToK(size, valueHash);

    val pooled2 = planReusePooledConnection(connect, connect.routes)
    if (pooled2 != null) return pooled2

    return connect
  }

  /**
   * Returns the connection already attached to the call if it's eligible for a new exchange.
   *
   * If the call's connection exists and is eligible for another exchange, it is returned. If it

        service.startAsync();
      } catch (IllegalStateException e) {
        // This can happen if the service has already been started or stopped (e.g. by another
        // service or listener). Our contract says it is safe to call this method if
        // all services were NEW when it was called, and this has already been verified above, so we
        // don't propagate the exception.

errors.login.failure = Falha no login.
errors.app.illegal.transition = Transição ilegal. Por favor, tente novamente.
errors.app.db.already.deleted = Pode ter sido excluído por outro processo. Por favor, tente novamente.
errors.app.db.already.updated = Pode ter sido atualizado por outro processo. Por favor, tente novamente.
errors.app.db.already.exists = Os dados já existem. Por favor, tente novamente.

  /**
   * Returns the last value corresponding to the specified field parsed as an HTTP date, or null if
   * either the field is absent or cannot be parsed as a date.
   */
  @IgnoreJRERequirement // Only programs that already have Instant will use this.
  fun getInstant(name: String): Instant? = getDate(name)?.toInstant()

  /** Returns the number of field values. */
  @get:JvmName("size")
  val size: Int
    get() = namesAndValues.size / 2