阅读以下代码并回答问题(1)-(3)。from sklearn.neighbors import KNeighborsClassifier
from sklearn import datasets
from sklearn.model_selection import train_test_split
wine = datasets.load_wine()
X = wine.data[:, [0, 2, 5]]
y = wine.target
train_X, test_X, train_y, test_y = \
train_test_split(X, y, test_size=0.25, random_state=42)
model = KNeighborsClassifier(n_neighbors=5)
model.fit(train_X, train_y)
(1)本代码采用的是什么学习类型的什么算法?该算法做的是什么工作?
(2)研究的是什么数据集?选择的特征是什么?
(3)test_size = 0.25 的含义是?model.fit(train_X, train_y) 的含义是?