/**
     * The elements of a {@link ConcurrentlyMutatedList} are added and removed over time. This
     * method returns every state that the list has passed through at some point.
     */
    Set<List<E>> getAllStates();
  }

  /**
   * Returns a {@link ConcurrentlyMutatedList} that performs the given operations as its concurrent

-flexbox!important;display:inline-flex!important}}@media print{.d-print-none{display:none!important}.d-print-inline{display:inline!important}.d-print-inline-block{display:inline-block!important}.d-print-block{display:block!important}.d-print-table{display:table!important}.d-print-table-row{display:table-row!important}.d-print-table-cell{display:table-cell!important}.d-print-flex{display:-ms-flexbox!important;display:flex!important}.d-print-inline-flex{display:-ms-inline-flexbox!important;display...

						var primaryKey, primaryKeySchema string
						if rf.PrimaryKey != nil {
							primaryKey, primaryKeySchema = rf.PrimaryKey.Name, rf.PrimaryKey.Schema.Name
						}
						refs = append(refs, fmt.Sprintf(
							"{PrimaryKey: %v PrimaryKeySchame: %v ForeignKey: %v ForeignKeySchema: %v PrimaryValue: %v OwnPrimaryKey: %v}",

```Python
with open("./somefile.txt") as f:
    contents = f.read()
    print(contents)
```

Por baixo dos panos, o código `open("./somefile.txt")` cria um objeto que é chamado de "Gerenciador de Contexto".

# We have some invalid linker scripts in the build,
# so we need to disable this check
build:release_linux_base --linkopt=-Wl,--undefined-version

# Container environment settings below this point.
# Test-related settings below this point.
test:release_linux_base --build_tests_only --keep_going --test_output=errors --verbose_failures=true
test:release_linux_base --local_test_jobs=HOST_CPUS

   * (though it still may be evicted by other means).
   *
   * <p><b>Important note:</b> Instead of returning this as a {@code CacheBuilder}
   * instance, this method returns {@code CacheBuilder<K1, V1>}. From this point on, either the
   * original reference or the returned reference may be used to complete configuration and build
   * the cache, but only the "generic" one is type-safe. That is, it will properly prevent you from

					continue
				}
				h := crc32.NewIEEE()
				_, err = io.CopyBuffer(h, tr, rdbuf) // Effectively an incremental read
				if err != nil {
					break
				}
				chksums = append(chksums, fmt.Sprintf("%x", h.Sum(nil)))
			}

			for i, hdr := range hdrs {
				if i >= len(v.headers) {
					t.Fatalf("entry %d: unexpected header:\ngot %+v", i, *hdr)
				}
				if !reflect.DeepEqual(*hdr, *v.headers[i]) {

   * LinearTransformation#mapping}. You almost certainly don't want to keep instances around, but
   * instead use method chaining. This represents a single point mapping, i.e. a mapping between one
   * {@code x} and {@code y} value pair.
   *
   * @since 20.0
   */
  public static final class LinearTransformationBuilder {

    private final double x1;

  [Environment]::SetEnvironmentVariable(\"PATH\", $env:PATH, \"Machine\"); \
  $env:JAVA_HOME = $zulu_root; \
  [Environment]::SetEnvironmentVariable(\"JAVA_HOME\", $env:JAVA_HOME, \"Machine\")

# Point to the LLVM installation.
# The Bazel Windows guide claims it can find LLVM automatically,
# but it likely only works if it's installed somewhere inside C:\Program Files.
ENV BAZEL_LLVM "C:\tools\LLVM"

Ví dụ, bạn có một file `main.py` với:

```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")
```

/// tip

Tham số thứ hai cho <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> là giá trị mặc định để trả về.