#' @param reshape logical, reshape the expanded data. If \code{TRUE}, then return a wide data frame with all water-quality in a single row for each sample.
#' If \code{FALSE} (default), then return a long data frame with each water-quality result in a single row. This
#' argument is only applicable to expanded data. Data requested using \code{expanded=FALSE} is always returned in the wide format.
#' @param tz character to set timezone attribute of datetime. Default is an empty quote, which converts the
#' datetimes to UTC (properly accounting for daylight savings times based on the data's provided tz_cd column).
#' @param tz character to set timezone attribute of output columns: startDateTime and endDateTime. Default is an empty quote, which converts the
#' datetimes to UTC (properly accounting for daylight savings times).
#' Possible values to provide are "America/New_York","America/Chicago", "America/Denver","America/Los_Angeles",
#' "America/Anchorage","America/Honolulu","America/Jamaica","America/Managua","America/Phoenix", and "America/Metlakatla"
#' @keywords data import USGS web service
#' @return A data frame with the following columns:
#' @return A data frame with at least the following columns:
#' \tabular{lll}{
#' Name \tab Type \tab Description \cr
#' agency_cd \tab character \tab The NWIS code for the agency reporting the data\cr
#' site_no \tab character \tab The USGS site number \cr
#' datetime \tab POSIXct \tab The date and time of the value converted to UTC (if asDateTime = TRUE), \cr
#' \tab character \tab or raw character string (if asDateTime = FALSE) \cr
#' tz_cd \tab character \tab The time zone code for datetime \cr
#' code \tab character \tab Any codes that qualify the corresponding value\cr
#' value \tab numeric \tab The numeric value for the parameter \cr
#' sample_dt \tab Date \tab The date the sample was collected \cr
#' sample_tm \tab character \tab The reported sample collection time \cr
#' startDateTime \tab POSIXct \tab Combining sample_dt and sample_tm, a date/time column is created, and converted into UTC
#' (unless the tz argument specifies a different time zone)\cr
#' endDateTime \tab POSIXct \tab If any sample_end_dt and sample_end_dt exist, this column is created similar to startDateTime\cr
#' }
#'
#' Further columns will be included depending on the requested output format (expanded = TRUE or FALSE).
#'
#'
#' There are also several useful attributes attached to the data frame:
#' \tabular{lll}{
#' Name \tab Type \tab Description \cr
#' url \tab character \tab The url used to generate the data \cr
#' queryTime \tab POSIXct \tab The time the data was returned \cr
#' comment \tab character \tab Header comments from the RDB file \cr
#' siteInfo \tab data.frame \tab A data frame containing information on the requested sites \cr
#' variableInfo \tab data.frame \tab A data frame containing information on the requested parameters \cr
#' siteInfo \tab dataframe \tab A data frame containing information on the requested sites \cr
#' variableInfo \tab dataframe \tab A data frame containing information on the requested parameters \cr
