### Question:
DefaultExtractorInput implements ExtractorInput { @Override public void resetPeekPosition() { peekBufferPosition = 0; } DefaultExtractorInput(DataSource dataSource, long position, long length); @Override int read(byte[] target, int offset, int length); @Override boolean readFully(byte[] target, int offset, int length, boolean allowEndOfInput); @Override void readFully(byte[] target, int offset, int length); @Override int skip(int length); @Override boolean skipFully(int length, boolean allowEndOfInput); @Override void skipFully(int length); @Override boolean peekFully(byte[] target, int offset, int length, boolean allowEndOfInput); @Override void peekFully(byte[] target, int offset, int length); @Override boolean advancePeekPosition(int length, boolean allowEndOfInput); @Override void advancePeekPosition(int length); @Override void resetPeekPosition(); @Override long getPeekPosition(); @Override long getPosition(); @Override long getLength(); @Override void setRetryPosition(long position, E e);  }### Answer:
@Test public void testResetPeekPosition() throws Exception { DefaultExtractorInput input = createDefaultExtractorInput(); byte[] target = new byte[TEST_DATA.length]; input.peekFully(target, 0, TEST_DATA.length); assertThat(Arrays.equals(TEST_DATA, target)).isTrue(); assertThat(input.getPosition()).isEqualTo(0); input.resetPeekPosition(); byte[] target2 = new byte[TEST_DATA.length]; input.peekFully(target2, 0, TEST_DATA.length); assertThat(Arrays.equals(TEST_DATA, target2)).isTrue(); try { input.peekFully(target, 0, 1); fail(); } catch (EOFException e) { } }