### Question:
CSVParser { @Nonnull public CSVParser setSeparatorChar (final char cSeparator) { if (cSeparator == CCSV.NULL_CHARACTER) throw new UnsupportedOperationException ("The separator character must be defined!"); m_cSeparatorChar = cSeparator; if (_anyCharactersAreTheSame ()) throw new UnsupportedOperationException ("The separator, quote, and escape characters must be different!"); return this; } CSVParser(); char getSeparatorChar(); @Nonnull CSVParser setSeparatorChar(final char cSeparator); char getQuoteChar(); @Nonnull CSVParser setQuoteChar(final char cQuoteChar); char getEscapeChar(); @Nonnull CSVParser setEscapeChar(final char cEscapeChar); boolean isStrictQuotes(); @Nonnull CSVParser setStrictQuotes(final boolean bStrictQuotes); boolean isIgnoreLeadingWhiteSpace(); @Nonnull CSVParser setIgnoreLeadingWhiteSpace(final boolean bIgnoreLeadingWhiteSpace); boolean isIgnoreQuotations(); @Nonnull CSVParser setIgnoreQuotations(final boolean bIgnoreQuotations); boolean isPending(); @Nullable ICommonsList <String> parseLineMulti(@Nullable final String sNextLine); @Nullable ICommonsList <String> parseLine(@Nullable final String sNextLine);  }### Answer:
@Test (expected = UnsupportedOperationException.class) public void testSeparatorCharacterCannotBeNull () { new CSVParser ().setSeparatorChar (CCSV.NULL_CHARACTER); }