fix code

hutool-core/src/main/java/cn/hutool/v7/core/io/CharSequenceReader.java

@@ -44,6 +44,15 @@ public class CharSequenceReader extends Reader {
 	 */
 	private int mark;
 
+	/**
+	 * 构造
+	 *
+	 * @param str {@link CharSequence}
+	 */
+	public CharSequenceReader(final CharSequence str) {
+		this(str, 0, Assert.notNull(str).length());
+	}
+
 	/**
 	 * 构造
 	 *