microsoft-azure-storage/src/com/microsoft/azure/storage/core/Utility.java
public static String getStandardHeaderValue(final HttpURLConnection conn, final String headerName) {
        final String headerValue = conn.getRequestProperty(headerName);

        // Coalesce null value
        return headerValue == null ? Constants.EMPTY_STRING : headerValue;
    }
public static String getStandardHeaderValue(final HttpURLConnection conn, final String headerName) {
        final String headerValue = conn.getRequestProperty(headerName);

        // Coalesce null value
        return headerValue == null ? Constants.EMPTY_STRING : headerValue;
    }
Returns the standard header value from the specified connection request, or an empty string if no header value
has been specified for the request.

@param conn
An <code>HttpURLConnection</code> object that represents the request.
@param headerName
A <code>String</code> that represents the name of the header being requested.

@return A <code>String</code> that represents the header value, or <code>null</code> if there is no corresponding
header value for <code>headerName</code>.