Please invoke the isValidColor method to check if the colors are valid in the other medthods.

1. private static boolean isValidColor(char color) - This method returns true if the color parameter corresponds to one of the following characters: 'R' (red), 'G' (green), 'B' (blue), 'Y' (yellow), '*" (black), ':' (white). public static String getHorizontalBars(int maxRows, int maxCols, int bars, char color1, char color2, char color3) - This method returns a string with a number of horizontal bars that correspond to the bars parameter. To compute the size of each horizontal bar, divide maxRows by the specified number of bars. The first horizontal bar will use color1, the second color2, and the third color3. If more than 3 bars are present, we will start again with color1. If the computed size for a horizontal bar is less than 1, or any of the colors is invalid, the method will return null and no diagram will be generated. The method MUST not rely on System.out.println(). For example, calling DrawingApp.getHorizontalBars(12, 10, 3, 'R', 'G', 'B'); will generate the string: RRRRRRRRRR RRRRRRRRRR RRRRRRRRRR RRRRRRRRRR GGGGGGGGGG GGGGGGGGGG GGGGGGGGGG GGGGGGGGGG BBBBBBBBBB TI public static String getFlag(int size, char color1, char color2, char color3) - This method returns a string where a triangle appears on the left size of the diagram, followed by horizontal lines. For example, calling DrawingApp.getFlag(9, 'R', !!, 'Y'); will generate the string: R..... RRYYYYYYY YYYYYYYYYYYYYYYYYYYYYY RRRYYYYYYYYYYY YYYYYYYYYYYYYYYYYYYYYYYYYY RRRRYYYYYYYYYYYYYYY RRRRRYYYYYYY YYYYYYY YYYYYYYYY RRRRRRYYYYYYYY YYYYYYYYYYYYYYYYYYYYYYYY RRRRRRRYYYYYYYY YYYYYY YYYYYYYYYYY RRRRRRRRYYYYYYYYYYY YYYYY RRRRRRRRR. RRRRRRRRR. RRRRRRRRY RRRRRRRYYY YYYYYY YYYYYYYY RRRRRRYYYYYY YYYYYYYYYYYYYYYYYYYYYYYY RRRRRYYYYYYYYY YYYYYYYYYYYYYYYYYYYYYYYYYY RRRRYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY RRRYYYYY YYYYYYYYY YYYYYYYY YYYYYY RRYYYYYYY ( R.: The diagram has a number of rows that corresponds to size * 2 and a number of colums that corresponds to size * 5. The first and last row will use color2 (except for the first character that will use color1). The center two rows will use color and the rest color3. The triangle will rely on color1 and will have a height corresponding to size * 2. If the size parameter is less than three, the method will return null and will not generate any diagram. For this method you can assume the colors are valid. The method MUST not rely on System.out.println(). public static String getVerticalBars(int maxRows, int maxCols, int bars, char color1, char color2, char color3) - This method returns a string with a number of vertical bars that correspond to the bars parameter. To compute the size of each vertical bar, divide maxCols by the specified number of bars. The first vertical bar will use color1, the second color2, and the third color3. If more than 3 bars are present, we will start again with color1. If the computed size for a vertical bar is less than 1, or any of the colors is invalid, the method will return null and no diagram will be generated. The method MUST not rely on System.out.println(). For example, calling DrawingApp.getVerticalBars(10, 12, 3, 'R', 'G', 'B'); will generate the string: RRRRGGGGBBBB RRRRGGGGBBBB RRRRGGGGBBBB RRRRGGGGBBBB RRRRGGGGBBBB RRRRGGGGBBBB RRRRGGGGBBBB RRRRGGGGBBBB RRRRGGGGBBBB RRRRGGGGBBBB