set attachment.

@param key   the key
@param value the value
@return context attachment
552468
public RpcInternalContext setAttachment(String key, Object value) {
        if (key == null) {
            return this;
        }
        if (!ATTACHMENT_ENABLE) {
            // 未开启附件传递功能，只能传递隐藏key("." 开头的Key）
            if (!isHiddenParamKey(key)) {
                return this;
            }
        } else {
            if (!isValidInternalParamKey(key)) { // 打开附件传递功能，只能传 "_" 和 "." 开头的Key
                throw new IllegalArgumentException("key must start with" + RpcConstants.INTERNAL_KEY_PREFIX
                    + " or " + RpcConstants.HIDE_KEY_PREFIX);
            }
        }
        if (value == null) {
            attachments.remove(key);
        } else {
            attachments.put(key, value);
        }
        return this;
    }
1175523
public Setting set(String group, String key, String value) {
		this.put(group, key, value);
		return this;
	}
1132719
public Postcard withIntegerArrayList(@Nullable String key, @Nullable ArrayList<Integer> value) {
        mBundle.putIntegerArrayList(key, value);
        return this;
    }
99358
public function putAttachment(string $key, string $value): MeasurementInterface
    {
        $this->attachments[$key] = $value;
        return $this;
    }
136629
@NonNull
    @Override
    public MutableDocument setString(@NonNull String key, String value) {
        return setValue(key, value);
    }
520314
public void addCustomArg(String key, String value) {
    this.customArgs = addToMap(key, value, this.customArgs);
  }
1085900
@SuppressWarnings("unchecked")
    public static <T> AttachmentKey<T> create(final Class<? super T> valueClass) {
        return new SimpleAttachmentKey(valueClass);
    }
729691
public Object setMetadata(String key, Object value) {
        return metadata.put(key, value);
    }
461374
public void set(String key, Object value) {
        if (value != null) put(key, value);
        else remove(key);
    }
313806
public Weld property(String key, Object value) {
        properties.put(key, value);
        return this;
    }
1231343
public B set(String key, int value) {
        this.data.put(key, value);
        return (B) this;
    }
68237
public static Object put(String key, Object value) {
        return value == null ? CONTEXT.remove(key) : CONTEXT.put(key, value);
    }
1112093
protected void setAttachmentsInternal(Map<String, ? extends Attachment> attachments) {
        if (attachments != null) {
            // this awkward looking way of doing things is to avoid marking the map as being
            // modified
            HashMap<String, Attachment> m = new HashMap<String, Attachment>();
            for (Map.Entry<String, ? extends Attachment> att : attachments.entrySet()) {
                m.put(att.getKey(), att.getValue());
            }
            this.attachments = SimpleChangeNotifyingMap.wrap(m);
        }
    }
100013
public Configuration set(String key, String value) {
    checkReadOnly();

    properties.put(key, value);
    return this;
  }
48072
public static Object putIfAbsent(String key, Object value) {
        return value == null ? CONTEXT.remove(key) : CONTEXT.putIfAbsent(key, value);
    }
457819
public T put(String key, T value) {
		return container.put(key, value);
	}
369077
public ContentValues put(String key, String value) {
        mValues.put(key, value);
        return this;
    }