public String getPrefix() {
        return prefix;
    }
Gets the optional prefix parameter and restricts the response to keys
that begin with the specified prefix. Use prefixes to separate a
bucket into different sets of keys, similar to how a file system organizes files
into directories.

@return The optional prefix parameter restricting the response to keys
        that begin with the specified prefix.

@see ListObjectsV2Request#setPrefix(String)
aws-java-sdk-s3/src/main/java/com/amazonaws/services/s3/model/ListObjectsV2Request.java