test_class.file: client/src/test/java/io/spine/grpc/MetadataConverterTest.java
test_class.identifier: MetadataConverterTest
test_case.body: @Test
      @DisplayName("return absent when converting empty Metadata")
      void processEmptyMetadata() {
          Metadata metadata = new Metadata();
  
          assertFalse(MetadataConverter.toError(metadata)
                                       .isPresent());
      }
test_case.class_method_signature: MetadataConverterTest.processEmptyMetadata()
test_case.full_signature: @Test @DisplayName("return absent when converting empty Metadata") void processEmptyMetadata()
test_case.identifier: processEmptyMetadata
test_case.invocations: assertFalse isPresent toError
test_case.modifiers: @Test @DisplayName("return absent when converting empty Metadata")
test_case.parameters: ()
test_case.return: void
test_case.signature: void processEmptyMetadata()
focal_class.declarator: ERROR_KEY_NAME = "spine-error-bin"
focal_class.modifier: private static final
focal_class.original_string: private static final String ERROR_KEY_NAME = "spine-error-bin";
focal_class.type: String
focal_class.var_name: ERROR_KEY_NAME
focal_class.declarator: KEY = Key.of(ERROR_KEY_NAME, BINARY_BYTE_MARSHALLER)
focal_class.modifier: @VisibleForTesting
      static final
focal_class.original_string: @VisibleForTesting
      static final Key<byte[]> KEY = Key.of(ERROR_KEY_NAME, BINARY_BYTE_MARSHALLER);
focal_class.type: Key<byte[]>
focal_class.var_name: KEY
focal_class.file: client/src/main/java/io/spine/grpc/MetadataConverter.java
focal_class.identifier: MetadataConverter
focal_class.class_method_signature: MetadataConverter.MetadataConverter()
focal_class.full_signature: private  MetadataConverter()
focal_class.identifier: MetadataConverter
focal_class.modifiers: private
focal_class.parameters: ()
focal_class.signature:  MetadataConverter()
focal_class.class_method_signature: MetadataConverter.toMetadata(Error error)
focal_class.full_signature: public static Metadata toMetadata(Error error)
focal_class.identifier: toMetadata
focal_class.modifiers: public static
focal_class.parameters: (Error error)
focal_class.return: Metadata
focal_class.signature: Metadata toMetadata(Error error)
focal_class.class_method_signature: MetadataConverter.toError(Metadata metadata)
focal_class.full_signature: public static Optional<Error> toError(Metadata metadata)
focal_class.identifier: toError
focal_class.modifiers: public static
focal_class.parameters: (Metadata metadata)
focal_class.return: Optional<Error>
focal_class.signature: Optional<Error> toError(Metadata metadata)
focal_method.body: public static Optional<Error> toError(Metadata metadata) {
          checkNotNull(metadata);
          byte[] bytes = metadata.get(KEY);
  
          if (bytes == null) {
              return Optional.empty();
          }
  
          try {
              Error error = Error.parseFrom(bytes);
              return Optional.of(error);
          } catch (InvalidProtocolBufferException e) {
              throw Exceptions.illegalStateWithCauseOf(e);
          }
      }
focal_method.class_method_signature: MetadataConverter.toError(Metadata metadata)
focal_method.full_signature: public static Optional<Error> toError(Metadata metadata)
focal_method.identifier: toError
focal_method.invocations: checkNotNull get empty parseFrom of illegalStateWithCauseOf
focal_method.modifiers: public static
focal_method.parameters: (Metadata metadata)
focal_method.return: Optional<Error>
focal_method.signature: Optional<Error> toError(Metadata metadata)