Returns the index of the first occurrence of the specified element
in this list, or -1 if this list does not contain the element.
More formally, returns the lowest index <tt>i</tt> such that
<tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>,
or -1 if there is no such index.
@param o element to search for
@return the index of the first occurrence of the specified element in
this list, or -1 if this list does not contain the element
@throws ClassCastException if the type of the specified element
is incompatible with this list
(<a href="Collection.html#optional-restrictions">optional</a>)
@throws NullPointerException if the specified element is null and this
list does not permit null elements
(<a href="Collection.html#optional-restrictions">optional</a>)
Returns the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element. More formally, returns the lowest index <tt>i</tt> such that <tt>(o==null ? get(i)==null : o.equals(get(i)))</tt>, or -1 if there is no such index.
@param o element to search for @return the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element @throws ClassCastException if the type of the specified element is incompatible with this list (<a href="Collection.html#optional-restrictions">optional</a>) @throws NullPointerException if the specified element is null and this list does not permit null elements (<a href="Collection.html#optional-restrictions">optional</a>)