##' @details
 ##'
 ##' The qmtools package provides six categories of important functions:
 ##'
 ##'  - Imputation: the [imputeIntensity] function performs data imputation on
 ##'  missing values.
 ##'  - Normalization: the [normalizeIntensity] function performs data-driven
 ##'  normalization on metabolomics data.
 ##'  - Feature filtering: the [removeFeatures] function removes uninformative
 ##'  features based on missing values, QC and blank samples.
 ##'  - Feature clustering: the [clusterFeatures] function clusters metabolic
 ##'  features according to their retention time and intensity correlation.
 ##'  - Dimension-reduction: the [reduceFeatures] function performs
 ##'  dimensionality reduction.
 ##'  - Visualization: the [plotBox], [plotCorr], [plotMiss], [plotReduced], and
 ##'  [plotRTgroup] functions help to visualize metabolomics data.
 ##'
 ##' Please refer to the vignette to see how the aforementioned functions work.
 ##'
 ##' @keywords internal
 ##'
 "_PACKAGE"