Fix COSIndirect to COSStream casts

Author: e-zhavoronok

src/main/java/org/verapdf/cos/COSStream.java

@@ -318,8 +318,8 @@ boolean equals(Object obj, List<COSBasePair> checkedObjects) {
 					entry.getKey() == ASAtom.LENGTH) {
 				continue;
 			}
-			COSBase cosBase = that.getKey(entry.getKey()).get();
-			if (!entry.getValue().get().equals(cosBase, checkedObjects)) {
+			COSBase cosBase = that.getKey(entry.getKey()).getDirectBase();
+			if (!entry.getValue().getDirectBase().equals(cosBase, checkedObjects)) {
 				return false;
 			}
 		}

src/test/java/org/verapdf/cos/COSStreamTest.java

@@ -44,7 +44,7 @@ public void test() throws IOException {
         ASInputStream asciiHexStream = new ASMemoryInStream(asciiHexData);
         COSObject cosStream = COSStream.construct(asciiHexStream);
         cosStream.setKey(ASAtom.FILTER, COSName.construct(ASAtom.ASCII_HEX_DECODE));
-        ((COSStream) cosStream.get()).setFilters(new COSFilters(COSName.construct(ASAtom.FLATE_DECODE)));
+        ((COSStream) cosStream.getDirectBase()).setFilters(new COSFilters(COSName.construct(ASAtom.FLATE_DECODE)));
         byte[] buf = new byte[100];
         int read = cosStream.getData(COSStream.FilterFlags.DECODE).read(buf, 100);
         String message = new String(Arrays.copyOf(buf, read), StandardCharsets.ISO_8859_1);